diff --git a/docs/source/sls/algorithm.rst b/docs/source/sls/algorithm.rst
index 5c3111610cb7a453904a0c1ebcf878efc0700004..49a98f1589a1a16631316064249ebbc30a962e0e 100644
--- a/docs/source/sls/algorithm.rst
+++ b/docs/source/sls/algorithm.rst
@@ -104,9 +104,12 @@ ERR数据单元构造误差数据，该步误差公式：
 
 .. math::
 
-    v = {\sigma}_1 \cdot {\sigma}_2
+\begin{displaymath}
+v = {\sigma}_1 \cdot {\sigma}_2
+\end{displaymath}
 
 \sigma = \sqrt{((SCI-bias)+\sigma^2 + readnoise^2)}
+
 **Dark correction**
 
 class: csst_ms_sls_instrument.steps.DarkCorrStep