diff --git a/models/activities/action.go b/models/activities/action.go
index 9b4ffd7725..c83dba9d46 100644
--- a/models/activities/action.go
+++ b/models/activities/action.go
@@ -171,7 +171,10 @@ func (a *Action) TableIndices() []*schemas.Index {
 	cudIndex := schemas.NewIndex("c_u_d", schemas.IndexType)
 	cudIndex.AddColumn("created_unix", "user_id", "is_deleted")
 
-	indices := []*schemas.Index{actUserIndex, repoIndex, cudIndex}
+	cuIndex := schemas.NewIndex("c_u", schemas.IndexType)
+	cuIndex.AddColumn("user_id", "is_deleted")
+
+	indices := []*schemas.Index{actUserIndex, repoIndex, cudIndex, cuIndex}
 
 	return indices
 }
diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 41f337b838..0333e7e204 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -365,6 +365,7 @@ func prepareMigrationTasks() []*migration {
 		newMigration(305, "Add Repository Licenses", v1_23.AddRepositoryLicenses),
 		newMigration(306, "Add BlockAdminMergeOverride to ProtectedBranch", v1_23.AddBlockAdminMergeOverrideBranchProtection),
 		newMigration(307, "Fix milestone deadline_unix when there is no due date", v1_23.FixMilestoneNoDueDate),
+		newMigration(308, "Add index(user_id, is_deleted) for action table", v1_23.AddNewIndexForUserDashboard),
 	}
 	return preparedMigrations
 }
diff --git a/models/migrations/v1_23/v308.go b/models/migrations/v1_23/v308.go
new file mode 100644
index 0000000000..1e8a9b0af2
--- /dev/null
+++ b/models/migrations/v1_23/v308.go
@@ -0,0 +1,52 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_23 //nolint
+
+import (
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/xorm"
+	"xorm.io/xorm/schemas"
+)
+
+type improveActionTableIndicesAction struct {
+	ID          int64 `xorm:"pk autoincr"`
+	UserID      int64 `xorm:"INDEX"` // Receiver user id.
+	OpType      int
+	ActUserID   int64 // Action user id.
+	RepoID      int64
+	CommentID   int64 `xorm:"INDEX"`
+	IsDeleted   bool  `xorm:"NOT NULL DEFAULT false"`
+	RefName     string
+	IsPrivate   bool               `xorm:"NOT NULL DEFAULT false"`
+	Content     string             `xorm:"TEXT"`
+	CreatedUnix timeutil.TimeStamp `xorm:"created"`
+}
+
+// TableName sets the name of this table
+func (*improveActionTableIndicesAction) TableName() string {
+	return "action"
+}
+
+func (a *improveActionTableIndicesAction) TableIndices() []*schemas.Index {
+	repoIndex := schemas.NewIndex("r_u_d", schemas.IndexType)
+	repoIndex.AddColumn("repo_id", "user_id", "is_deleted")
+
+	actUserIndex := schemas.NewIndex("au_r_c_u_d", schemas.IndexType)
+	actUserIndex.AddColumn("act_user_id", "repo_id", "created_unix", "user_id", "is_deleted")
+
+	cudIndex := schemas.NewIndex("c_u_d", schemas.IndexType)
+	cudIndex.AddColumn("created_unix", "user_id", "is_deleted")
+
+	cuIndex := schemas.NewIndex("c_u", schemas.IndexType)
+	cuIndex.AddColumn("user_id", "is_deleted")
+
+	indices := []*schemas.Index{actUserIndex, repoIndex, cudIndex, cuIndex}
+
+	return indices
+}
+
+func AddNewIndexForUserDashboard(x *xorm.Engine) error {
+	return x.Sync(new(improveActionTableIndicesAction))
+}