diff --git a/api/schedule/clean_unused_datasets_task.py b/api/schedule/clean_unused_datasets_task.py
index 2033791ace..9cbee6e81e 100644
--- a/api/schedule/clean_unused_datasets_task.py
+++ b/api/schedule/clean_unused_datasets_task.py
@@ -2,6 +2,7 @@ import datetime
 import time
 
 import click
+from sqlalchemy import func
 from werkzeug.exceptions import NotFound
 
 import app
@@ -20,10 +21,46 @@ def clean_unused_datasets_task():
     page = 1
     while True:
         try:
-            datasets = db.session.query(Dataset).filter(Dataset.created_at < thirty_days_ago) \
-                .order_by(Dataset.created_at.desc()).paginate(page=page, per_page=50)
+            # Subquery for counting new documents
+            document_subquery_new = db.session.query(
+                Document.dataset_id,
+                func.count(Document.id).label('document_count')
+            ).filter(
+                Document.indexing_status == 'completed',
+                Document.enabled == True,
+                Document.archived == False,
+                Document.updated_at > thirty_days_ago
+            ).group_by(Document.dataset_id).subquery()
+
+            # Subquery for counting old documents
+            document_subquery_old = db.session.query(
+                Document.dataset_id,
+                func.count(Document.id).label('document_count')
+            ).filter(
+                Document.indexing_status == 'completed',
+                Document.enabled == True,
+                Document.archived == False,
+                Document.updated_at < thirty_days_ago
+            ).group_by(Document.dataset_id).subquery()
+
+            # Main query with join and filter
+            datasets = (db.session.query(Dataset)
+                        .outerjoin(
+                document_subquery_new, Dataset.id == document_subquery_new.c.dataset_id
+            ).outerjoin(
+                document_subquery_old, Dataset.id == document_subquery_old.c.dataset_id
+            ).filter(
+                Dataset.created_at < thirty_days_ago,
+                func.coalesce(document_subquery_new.c.document_count, 0) == 0,
+                func.coalesce(document_subquery_old.c.document_count, 0) > 0
+            ).order_by(
+                Dataset.created_at.desc()
+            ).paginate(page=page, per_page=50))
+
         except NotFound:
             break
+        if datasets.items is None or len(datasets.items) == 0:
+            break
         page += 1
         for dataset in datasets:
             dataset_query = db.session.query(DatasetQuery).filter(
@@ -31,31 +68,23 @@ def clean_unused_datasets_task():
                 DatasetQuery.dataset_id == dataset.id
             ).all()
             if not dataset_query or len(dataset_query) == 0:
-                documents = db.session.query(Document).filter(
-                    Document.dataset_id == dataset.id,
-                    Document.indexing_status == 'completed',
-                    Document.enabled == True,
-                    Document.archived == False,
-                    Document.updated_at > thirty_days_ago
-                ).all()
-                if not documents or len(documents) == 0:
-                    try:
-                        # remove index
-                        index_processor = IndexProcessorFactory(dataset.doc_form).init_index_processor()
-                        index_processor.clean(dataset, None)
+                try:
+                    # remove index
+                    index_processor = IndexProcessorFactory(dataset.doc_form).init_index_processor()
+                    index_processor.clean(dataset, None)
 
-                        # update document
-                        update_params = {
-                            Document.enabled: False
-                        }
+                    # update document
+                    update_params = {
+                        Document.enabled: False
+                    }
 
-                        Document.query.filter_by(dataset_id=dataset.id).update(update_params)
-                        db.session.commit()
-                        click.echo(click.style('Cleaned unused dataset {} from db success!'.format(dataset.id),
-                                               fg='green'))
-                    except Exception as e:
-                        click.echo(
-                            click.style('clean dataset index error: {} {}'.format(e.__class__.__name__, str(e)),
-                                        fg='red'))
+                    Document.query.filter_by(dataset_id=dataset.id).update(update_params)
+                    db.session.commit()
+                    click.echo(click.style('Cleaned unused dataset {} from db success!'.format(dataset.id),
+                                           fg='green'))
+                except Exception as e:
+                    click.echo(
+                        click.style('clean dataset index error: {} {}'.format(e.__class__.__name__, str(e)),
+                                    fg='red'))
     end_at = time.perf_counter()
     click.echo(click.style('Cleaned unused dataset from db success latency: {}'.format(end_at - start_at), fg='green'))