diff --git a/aaa/kcl.mod b/aaa/kcl.mod
new file mode 100644
index 00000000..60f561a7
--- /dev/null
+++ b/aaa/kcl.mod
@@ -0,0 +1,4 @@
+[package]
+name = "aaa"
+edition = "0.0.1"
+version = "0.0.1"
diff --git a/aaa/kcl.mod.lock b/aaa/kcl.mod.lock
new file mode 100644
index 00000000..e69de29b
diff --git a/aaa/main.k b/aaa/main.k
new file mode 100644
index 00000000..fa7048e6
--- /dev/null
+++ b/aaa/main.k
@@ -0,0 +1 @@
+The_first_kcl_program = 'Hello World!'
\ No newline at end of file
diff --git a/pkg/client/client.go b/pkg/client/client.go
index fdff57f8..5fb8f2f5 100644
--- a/pkg/client/client.go
+++ b/pkg/client/client.go
@@ -1104,7 +1104,10 @@ func (c *KpmClient) downloadDeps(deps pkg.Dependencies, lockDeps pkg.Dependencie
 		}
 
 		if !lockedDep.IsFromLocal() {
-			if !c.noSumCheck && expectedSum != "" && lockedDep.Sum != expectedSum && existDep.FullName == d.FullName {
+			if !c.noSumCheck && expectedSum != "" &&
+				lockedDep.Sum != expectedSum &&
+				existDep != nil &&
+				existDep.FullName == d.FullName {
 				return nil, reporter.NewErrorEvent(
 					reporter.CheckSumMismatch,
 					errors.CheckSumMismatchError,
diff --git a/pkg/client/client_test.go b/pkg/client/client_test.go
index dbf95168..61062d11 100644
--- a/pkg/client/client_test.go
+++ b/pkg/client/client_test.go
@@ -874,3 +874,127 @@ func TestUpdateWithNoSumCheck(t *testing.T) {
 		_ = os.Remove(filepath.Join(pkgPath, "kcl.mod.lock"))
 	}()
 }
+
+func TestAddWithDiffVersionNoSumCheck(t *testing.T) {
+	pkgPath := getTestDir("test_add_diff_version")
+
+	pkgWithSumCheckPath := filepath.Join(pkgPath, "no_sum_check")
+	pkgWithSumCheckPathModBak := filepath.Join(pkgWithSumCheckPath, "kcl.mod.bak")
+	pkgWithSumCheckPathMod := filepath.Join(pkgWithSumCheckPath, "kcl.mod")
+	pkgWithSumCheckPathModExpect := filepath.Join(pkgWithSumCheckPath, "kcl.mod.expect")
+	pkgWithSumCheckPathModLock := filepath.Join(pkgWithSumCheckPath, "kcl.mod.lock")
+
+	err := copy.Copy(pkgWithSumCheckPathModBak, pkgWithSumCheckPathMod)
+	assert.Equal(t, err, nil)
+
+	kpmcli, err := NewKpmClient()
+	assert.Equal(t, err, nil)
+	kclPkg, err := kpmcli.LoadPkgFromPath(pkgWithSumCheckPath)
+	assert.Equal(t, err, nil)
+
+	opts := opt.AddOptions{
+		LocalPath: pkgPath,
+		RegistryOpts: opt.RegistryOptions{
+			Oci: &opt.OciOptions{
+				Reg:     "ghcr.io",
+				Repo:    "kcl-lang",
+				PkgName: "helloworld",
+				Tag:     "0.1.1",
+			},
+		},
+		NoSumCheck: true,
+	}
+
+	_, err = kpmcli.AddDepWithOpts(kclPkg, &opts)
+	assert.Equal(t, err, nil)
+	assert.Equal(t, utils.DirExists(pkgWithSumCheckPathModLock), false)
+
+	modContent, err := os.ReadFile(pkgWithSumCheckPathMod)
+	modContentStr := strings.ReplaceAll(string(modContent), "\r\n", "")
+	modContentStr = strings.ReplaceAll(string(modContentStr), "\n", "")
+	assert.Equal(t, err, nil)
+	modExpectContent, err := os.ReadFile(pkgWithSumCheckPathModExpect)
+	modExpectContentStr := strings.ReplaceAll(string(modExpectContent), "\r\n", "")
+	modExpectContentStr = strings.ReplaceAll(modExpectContentStr, "\n", "")
+	assert.Equal(t, err, nil)
+	assert.Equal(t, modContentStr, modExpectContentStr)
+
+	opts.NoSumCheck = false
+	_, err = kpmcli.AddDepWithOpts(kclPkg, &opts)
+	assert.Equal(t, err, nil)
+	assert.Equal(t, utils.DirExists(pkgWithSumCheckPathModLock), true)
+	modContent, err = os.ReadFile(pkgWithSumCheckPathMod)
+	modContentStr = strings.ReplaceAll(string(modContent), "\r\n", "")
+	modContentStr = strings.ReplaceAll(modContentStr, "\n", "")
+	assert.Equal(t, err, nil)
+	assert.Equal(t, modContentStr, modExpectContentStr)
+
+	defer func() {
+		_ = os.Remove(pkgWithSumCheckPathMod)
+		_ = os.Remove(pkgWithSumCheckPathModLock)
+	}()
+}
+
+func TestAddWithDiffVersionWithSumCheck(t *testing.T) {
+	pkgPath := getTestDir("test_add_diff_version")
+
+	pkgWithSumCheckPath := filepath.Join(pkgPath, "with_sum_check")
+	pkgWithSumCheckPathModBak := filepath.Join(pkgWithSumCheckPath, "kcl.mod.bak")
+	pkgWithSumCheckPathMod := filepath.Join(pkgWithSumCheckPath, "kcl.mod")
+	pkgWithSumCheckPathModExpect := filepath.Join(pkgWithSumCheckPath, "kcl.mod.expect")
+	pkgWithSumCheckPathModLock := filepath.Join(pkgWithSumCheckPath, "kcl.mod.lock")
+	pkgWithSumCheckPathModLockBak := filepath.Join(pkgWithSumCheckPath, "kcl.mod.lock.bak")
+	pkgWithSumCheckPathModLockExpect := filepath.Join(pkgWithSumCheckPath, "kcl.mod.lock.expect")
+
+	err := copy.Copy(pkgWithSumCheckPathModBak, pkgWithSumCheckPathMod)
+	assert.Equal(t, err, nil)
+	err = copy.Copy(pkgWithSumCheckPathModLockBak, pkgWithSumCheckPathModLock)
+	assert.Equal(t, err, nil)
+
+	kpmcli, err := NewKpmClient()
+	assert.Equal(t, err, nil)
+	kclPkg, err := kpmcli.LoadPkgFromPath(pkgWithSumCheckPath)
+	assert.Equal(t, err, nil)
+
+	opts := opt.AddOptions{
+		LocalPath: pkgPath,
+		RegistryOpts: opt.RegistryOptions{
+			Oci: &opt.OciOptions{
+				Reg:     "ghcr.io",
+				Repo:    "kcl-lang",
+				PkgName: "helloworld",
+				Tag:     "0.1.1",
+			},
+		},
+	}
+
+	_, err = kpmcli.AddDepWithOpts(kclPkg, &opts)
+	assert.Equal(t, err, nil)
+
+	modContent, err := os.ReadFile(pkgWithSumCheckPathMod)
+	modContentStr := strings.ReplaceAll(string(modContent), "\r\n", "")
+	modContentStr = strings.ReplaceAll(modContentStr, "\n", "")
+	assert.Equal(t, err, nil)
+
+	modExpectContent, err := os.ReadFile(pkgWithSumCheckPathModExpect)
+	modExpectContentStr := strings.ReplaceAll(string(modExpectContent), "\r\n", "")
+	modExpectContentStr = strings.ReplaceAll(modExpectContentStr, "\n", "")
+
+	assert.Equal(t, err, nil)
+	assert.Equal(t, modContentStr, modExpectContentStr)
+
+	modLockContent, err := os.ReadFile(pkgWithSumCheckPathModLock)
+	modLockContentStr := strings.ReplaceAll(string(modLockContent), "\r\n", "")
+	modLockContentStr = strings.ReplaceAll(modLockContentStr, "\n", "")
+	assert.Equal(t, err, nil)
+	modLockExpectContent, err := os.ReadFile(pkgWithSumCheckPathModLockExpect)
+	modLockExpectContentStr := strings.ReplaceAll(string(modLockExpectContent), "\r\n", "")
+	modLockExpectContentStr = strings.ReplaceAll(modLockExpectContentStr, "\n", "")
+	assert.Equal(t, err, nil)
+	assert.Equal(t, modLockContentStr, modLockExpectContentStr)
+
+	defer func() {
+		_ = os.Remove(pkgWithSumCheckPathMod)
+		_ = os.Remove(pkgWithSumCheckPathModLock)
+	}()
+}
diff --git a/pkg/client/test_data/test_add_diff_version/no_sum_check/kcl.mod.bak b/pkg/client/test_data/test_add_diff_version/no_sum_check/kcl.mod.bak
new file mode 100644
index 00000000..126d4126
--- /dev/null
+++ b/pkg/client/test_data/test_add_diff_version/no_sum_check/kcl.mod.bak
@@ -0,0 +1,7 @@
+[package]
+name = "no_sum_check"
+edition = "0.0.1"
+version = "0.0.1"
+
+[dependencies]
+helloworld = "0.1.0"
diff --git a/pkg/client/test_data/test_add_diff_version/no_sum_check/kcl.mod.expect b/pkg/client/test_data/test_add_diff_version/no_sum_check/kcl.mod.expect
new file mode 100644
index 00000000..f77d425c
--- /dev/null
+++ b/pkg/client/test_data/test_add_diff_version/no_sum_check/kcl.mod.expect
@@ -0,0 +1,7 @@
+[package]
+name = "no_sum_check"
+edition = "0.0.1"
+version = "0.0.1"
+
+[dependencies]
+helloworld = "0.1.1"
diff --git a/pkg/client/test_data/test_add_diff_version/no_sum_check/main.k b/pkg/client/test_data/test_add_diff_version/no_sum_check/main.k
new file mode 100644
index 00000000..fa7048e6
--- /dev/null
+++ b/pkg/client/test_data/test_add_diff_version/no_sum_check/main.k
@@ -0,0 +1 @@
+The_first_kcl_program = 'Hello World!'
\ No newline at end of file
diff --git a/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.bak b/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.bak
new file mode 100644
index 00000000..a29e213d
--- /dev/null
+++ b/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.bak
@@ -0,0 +1,7 @@
+[package]
+name = "with_sum_check"
+edition = "0.0.1"
+version = "0.0.1"
+
+[dependencies]
+helloworld = "0.1.0"
diff --git a/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.expect b/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.expect
new file mode 100644
index 00000000..36ec88e0
--- /dev/null
+++ b/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.expect
@@ -0,0 +1,7 @@
+[package]
+name = "with_sum_check"
+edition = "0.0.1"
+version = "0.0.1"
+
+[dependencies]
+helloworld = "0.1.1"
diff --git a/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.lock.bak b/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.lock.bak
new file mode 100644
index 00000000..b57cac07
--- /dev/null
+++ b/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.lock.bak
@@ -0,0 +1,9 @@
+[dependencies]
+  [dependencies.helloworld]
+    name = "helloworld"
+    full_name = "helloworld_0.1.0"
+    version = "0.1.0"
+    sum = "aqrvSsd8zGHzRERbOzxYxARmK6QjvpQMYC1OqemdZvc="
+    reg = "ghcr.io"
+    repo = "kcl-lang/helloworld"
+    oci_tag = "0.1.1"
diff --git a/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.lock.expect b/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.lock.expect
new file mode 100644
index 00000000..6270d4f4
--- /dev/null
+++ b/pkg/client/test_data/test_add_diff_version/with_sum_check/kcl.mod.lock.expect
@@ -0,0 +1,9 @@
+[dependencies]
+  [dependencies.helloworld]
+    name = "helloworld"
+    full_name = "helloworld_0.1.1"
+    version = "0.1.1"
+    sum = "7OO4YK2QuRWPq9C7KTzcWcti5yUnueCjptT3OXiPVeQ="
+    reg = "ghcr.io"
+    repo = "kcl-lang/helloworld"
+    oci_tag = "0.1.1"
diff --git a/pkg/client/test_data/test_add_diff_version/with_sum_check/main.k b/pkg/client/test_data/test_add_diff_version/with_sum_check/main.k
new file mode 100644
index 00000000..fa7048e6
--- /dev/null
+++ b/pkg/client/test_data/test_add_diff_version/with_sum_check/main.k
@@ -0,0 +1 @@
+The_first_kcl_program = 'Hello World!'
\ No newline at end of file