diff --git a/be/src/olap/rowset/segment_v2/ann_index/faiss_ann_index.cpp b/be/src/olap/rowset/segment_v2/ann_index/faiss_ann_index.cpp
index e4d6061941eeb1..621fe7fe4eecab 100644
--- a/be/src/olap/rowset/segment_v2/ann_index/faiss_ann_index.cpp
+++ b/be/src/olap/rowset/segment_v2/ann_index/faiss_ann_index.cpp
@@ -222,8 +222,8 @@ struct FaissIndexReader : faiss::IOReader {
     lucene::store::IndexInput* _input = nullptr;
 };
 
-doris::Status FaissVectorIndex::train(vectorized::Int64 n, const float* x) {
-    DCHECK(x != nullptr);
+doris::Status FaissVectorIndex::train(vectorized::Int64 n, const float* vec) {
+    DCHECK(vec != nullptr);
     DCHECK(_index != nullptr);
 
     // For PQ index, check if we have enough training data
@@ -239,9 +239,8 @@ doris::Status FaissVectorIndex::train(vectorized::Int64 n, const float* x) {
     ScopedThreadName scoped_name("faiss_train_idx");
     // Reserve OpenMP threads globally so concurrent builds stay under omp_threads_limit.
     ScopedOmpThreadBudget thread_budget;
-    omp_set_num_threads(config::omp_threads_limit);
     try {
-        _index->train(n, x);
+        _index->train(n, vec);
     } catch (faiss::FaissException& e) {
         return doris::Status::RuntimeError("exception occurred during training: {}", e.what());
     }
diff --git a/be/src/olap/rowset/segment_v2/ann_index/faiss_ann_index.h b/be/src/olap/rowset/segment_v2/ann_index/faiss_ann_index.h
index 8d8e3354f5f91a..c06402157aeccc 100644
--- a/be/src/olap/rowset/segment_v2/ann_index/faiss_ann_index.h
+++ b/be/src/olap/rowset/segment_v2/ann_index/faiss_ann_index.h
@@ -178,7 +178,18 @@ class FaissVectorIndex : public VectorIndex {
 
     ~FaissVectorIndex();
 
-    doris::Status train(vectorized::Int64 n, const float* x) override;
+    /**
+     * @brief Trains the index with the provided data.
+     *
+     * This method is used to train the FAISS index with a set of vectors.
+     * Training is required for certain index types that need to learn
+     * parameters from the data before adding vectors.
+     *
+     * @param n Number of training vectors
+     * @param vec Pointer to training vector data (n * dim float values)
+     * @return Status indicating success or failure
+     */
+    doris::Status train(vectorized::Int64 n, const float* vec) override;
 
     /**
      * @brief Adds vectors to the index for future searches.