diff --git a/docs/design_docs/datanode_flowgraph_recovery_design_0604_2021.md b/docs/design_docs/datanode_flowgraph_recovery_design_0604_2021.md
index 4ea8b2a2a3..89b7dee081 100644
--- a/docs/design_docs/datanode_flowgraph_recovery_design_0604_2021.md
+++ b/docs/design_docs/datanode_flowgraph_recovery_design_0604_2021.md
@@ -7,7 +7,7 @@ update: 6.21.2021, by [Goose](https://github.com/XuanYang-cn)
 
 A. One message stream to one vchannel, so there are one start position and one end position in one message pack.
 
-B. Only when datanode flushes, datanode will update every segment's position.
+B. Only when DataNode flushes, DataNode will update every segment's position.
 An optimization: update position of
 
 1. Current flushing segment
@@ -29,7 +29,7 @@ When a flowgraph flushes a segment, we need to save these things:
 
 - current segment's binlog paths.
 - current segment positions.
-- all other segments' current positions from the replica (If a segment hasn't been flushed, save the position when datanode first meets it).
+- all other segments' current positions from the replica (If a segment hasn't been flushed, save the position when DataNode first meets it).
 
 Whether save successfully: