diff --git a/metagpt/rag/factories/retriever.py b/metagpt/rag/factories/retriever.py
index c3d3a4f80..3342b8905 100644
--- a/metagpt/rag/factories/retriever.py
+++ b/metagpt/rag/factories/retriever.py
@@ -28,7 +28,8 @@ from metagpt.rag.schema import (
     ChromaRetrieverConfig,
     ElasticsearchKeywordRetrieverConfig,
     ElasticsearchRetrieverConfig,
-    FAISSRetrieverConfig, MilvusRetrieverConfig,
+    FAISSRetrieverConfig,
+    MilvusRetrieverConfig,
 )
 
 
@@ -138,7 +139,7 @@ class RetrieverFactory(ConfigBasedFactory):
 
     @get_or_build_index
     def _build_milvus_index(self, config: MilvusRetrieverConfig, **kwargs) -> VectorStoreIndex:
-        vector_store = MilvusVectorStore(uri=config.uri, collection_name=config.collection_name, token=config.token)
+        vector_store = MilvusVectorStore(uri=config.uri, collection_name=config.collection_name, token=config.token, dim=config.dimensions)
 
         return self._build_index_from_vector_store(config, vector_store, **kwargs)
 
diff --git a/metagpt/rag/schema.py b/metagpt/rag/schema.py
index 89e189235..e4d97068d 100644
--- a/metagpt/rag/schema.py
+++ b/metagpt/rag/schema.py
@@ -8,7 +8,7 @@ from llama_index.core.embeddings import BaseEmbedding
 from llama_index.core.indices.base import BaseIndex
 from llama_index.core.schema import TextNode
 from llama_index.core.vector_stores.types import VectorStoreQueryMode
-from pydantic import BaseModel, ConfigDict, Field, PrivateAttr, model_validator
+from pydantic import BaseModel, ConfigDict, Field, PrivateAttr, model_validator, validator
 
 from metagpt.config2 import config
 from metagpt.configs.embedding_config import EmbeddingType
@@ -71,6 +71,25 @@ class MilvusRetrieverConfig(IndexRetrieverConfig):
     metadata: Optional[CollectionMetadata] = Field(
         default=None, description="Optional metadata to associate with the collection"
     )
+    dimensions: int = Field(default=0, description="Dimensionality of the vectors for Milvus index construction.")
+
+    _embedding_type_to_dimensions: ClassVar[dict[EmbeddingType, int]] = {
+        EmbeddingType.GEMINI: 768,
+        EmbeddingType.OLLAMA: 4096,
+    }
+
+    @model_validator(mode="after")
+    def check_dimensions(self):
+        if self.dimensions == 0:
+            self.dimensions = config.embedding.dimensions or self._embedding_type_to_dimensions.get(
+                config.embedding.api_type, 1536
+            )
+            if not config.embedding.dimensions and config.embedding.api_type not in self._embedding_type_to_dimensions:
+                logger.warning(
+                    f"You didn't set dimensions in config when using {config.embedding.api_type}, default to 1536"
+                )
+
+        return self
 
 
 class ChromaRetrieverConfig(IndexRetrieverConfig):
diff --git a/tests/metagpt/rag/factories/test_index.py b/tests/metagpt/rag/factories/test_index.py
index 5d8711f9f..9861e1242 100644
--- a/tests/metagpt/rag/factories/test_index.py
+++ b/tests/metagpt/rag/factories/test_index.py
@@ -69,7 +69,6 @@ class TestRAGIndexFactory:
     ):
         self.index_factory.get_index(bm25_config, embed_model=mock_embedding)
 
-
     def test_create_milvus_index(self, mocker, milvus_config, mock_from_vector_store, mock_embedding):
         # Mock
         mock_milvus_store = mocker.patch("metagpt.rag.factories.index.MilvusVectorStore")
diff --git a/tests/metagpt/rag/factories/test_retriever.py b/tests/metagpt/rag/factories/test_retriever.py
index 149e4b172..b808de26e 100644
--- a/tests/metagpt/rag/factories/test_retriever.py
+++ b/tests/metagpt/rag/factories/test_retriever.py
@@ -99,7 +99,7 @@ class TestRetrieverFactory:
         assert isinstance(retriever, ChromaRetriever)
 
     def test_get_retriever_with_milvus_config(self, mocker, mock_milvus_vector_store, mock_embedding):
-        mock_config = MilvusRetrieverConfig(uri="/path/to/milvus", collection_name="test_collection")
+        mock_config = MilvusRetrieverConfig(uri="/path/to/milvus.db", collection_name="test_collection")
         mocker.patch("metagpt.rag.factories.retriever.MilvusVectorStore", return_value=mock_milvus_vector_store)
 
         retriever = self.retriever_factory.get_retriever(configs=[mock_config], nodes=[], embed_model=mock_embedding)