Abstract: It is of great significance to reduce the underground water level at the bottom and both sides of the channel to ensure the stability of the slope and the safety of the large open channel. Taking the Laizhou section of the Yellow River Water Diversion Project in Jiaodong,Shandong Province as the research object,a two-dimensional hydro-geological model and a seepage model of the channel slope are established to quantitatively analyze the pressure relief effect of drainage pipes with different heights and horizontal distances on both sides of the channel.According to the variation law of total water head and pore water pressure at different drainage pipe positions,the optimal drainage and pressure reduction position is determined. The results show that the best location for the effect of drainage is 0.1～0.125 m from the side of the canal. In addition,the drainage pipe positions of different sedimentation carrying capacity channels are studied,which serves as a basis for the reasonable drainage pipe arrangement in different channels,maximizing drainage and depressurization effect and preventing uplift pressure damage of channels.