道光二十三年的黃河中游大量降雨，使黃河、沁河水位暴漲，位於河南省中牟縣境內的中牟下汛九堡一帶大堤潰決，洪水經河南南部，再經安徽北部，最後進入洪澤湖。為堵截洪水，清廷先後動員眾多菁英官員，耗費鉅資，在一年半間興築中牟大工，期能將決口處堵合，並使黃河歸復故道。然而，中牟大工的修建並不順利，在道光二十四年初功敗垂成，但在鍾祥和鄂順安等人不懈的努力下，終在同年底合龍成功。本文對災害發生經過、清帝之決策與執事官員之用事、大工之興築與合龍、安徽巡撫與江南河道總督之相關因應、經費之調撥、賑卹與蠲免和災害範圍等進行考察，以探析清廷對道光二十三年黃河水患的防治之策。

The Heavy rain in 1843 causes the flood of the Yellow river and Qin River. The dike of eighth watcher station is broken through by Yellow flood peaks in the sixth lunar month, and quickly flows to Henan, Anhui, and Jiangsu provinces. In order to repair the dike quickly, officials begin to collect materials and construct Zhongmou debacle, but it's not the easiest party, they failed in 2nd lunar month 1844. By the new design of debacle and officers' unremitting effort, they finally succeed by the end of the same year. This article focus on two parts: first part is on Emperor, officers and Zhongmou debacle's construction, second part is the estimate of beget and effected areas.