Abstract: Hu Shi and Gu Tinglong cooperated to study the authenticity of Shuijingzhu proofread by Quan Zuwang. The key to this study depends on the re-proofread edition colleted in Hezhong Library. Through their letters and Gu Tinglong’s Shou Zha Shi Yu, we can restore how Hu Shi gradually changed his views with the help of Gu Tinglong. Although Hu Shi finally revised his conclusion, he achieved the purpose of redressing the injustice for Dai Zhen. Hu Shi’s success in the study is built on the successful textual research method.