diff --git a/python/sglang/srt/hf_transformers_utils.py b/python/sglang/srt/hf_transformers_utils.py
index c3abf11e4..7a8751043 100644
--- a/python/sglang/srt/hf_transformers_utils.py
+++ b/python/sglang/srt/hf_transformers_utils.py
@@ -88,19 +88,23 @@ CONTEXT_LENGTH_KEYS = [
 
 
 def get_context_length(config):
-    """Get the context length of a model from a huggingface model configs."""
-    rope_scaling = getattr(config, "rope_scaling", None)
+    """Get the context length of a model from a huggingface model configs.
+    And here the config should be text_config part if the model is a multimodal
+    LLM.
+    """
+    text_config = getattr(config, "text_config", config)
+    rope_scaling = getattr(text_config, "rope_scaling", None)
     if rope_scaling:
-        rope_scaling_factor = config.rope_scaling.get("factor", 1)
+        rope_scaling_factor = rope_scaling.get("factor", 1)
         if "original_max_position_embeddings" in rope_scaling:
             rope_scaling_factor = 1
-        if config.rope_scaling.get("rope_type", None) == "llama3":
+        if rope_scaling.get("rope_type", None) == "llama3":
             rope_scaling_factor = 1
     else:
         rope_scaling_factor = 1
 
     for key in CONTEXT_LENGTH_KEYS:
-        val = getattr(config, key, None)
+        val = getattr(text_config, key, None)
         if val is not None:
             return int(rope_scaling_factor * val)
     return 2048