diff --git a/scripts/diffusion/gen_smoke_data.py b/scripts/diffusion/gen_smoke_data.py
index 839f8f2..6a9634e 100644
--- a/scripts/diffusion/gen_smoke_data.py
+++ b/scripts/diffusion/gen_smoke_data.py
@@ -75,8 +75,9 @@ def main():
     print(f"Wrote {N_SAMPLES} samples to {csv_path}")
 
     # null vectors（空提示的 embedding，用于 cfg dropout）
-    null_t5   = torch.zeros(1, T5_SEQ, T5_DIM)
-    null_clip = torch.zeros(1, CLIP_DIM)
+    # 必须用 bf16，与训练 dtype 一致（train.py 加载后不做 dtype 转换）
+    null_t5   = torch.zeros(1, T5_SEQ, T5_DIM, dtype=torch.bfloat16)
+    null_clip = torch.zeros(1, CLIP_DIM, dtype=torch.bfloat16)
     torch.save(null_t5,   f"{NULL_DIR}/null_t5.pt")
     torch.save(null_clip, f"{NULL_DIR}/null_clip.pt")
     print(f"Wrote null vectors to {NULL_DIR}/")