Based on Hang-Ping-Sheng line waterway upgrading project in Pinghu City, considering effect of old revetment, the simulating the dredging experiment of sheet pile revetment with different cantilever length of sheet pile is implemented by the finite element software, then the comparative analysis is conducted for the horizontal displacement, internal stress and stability of revetment of sheet pile revetment with different cantilever length of sheet pile. In addition, the study of influence rule of cantilever length on sheet pile revetment is extended under the condition of different embedded depth. The results show that cantilever length of sheet pilehas obvious influence on deformation and trend of failure of revetment in the overlapping region of sheet pile and old revetment, but it has a very little influence on internal stress of sheet pile. In the overlapping region, the decreasing of cantilever length of sheet pile is conducive to stability of revetment, but when the top of sheet pile is lower than the bottom of old revetment, with the decreasing of cantilever length of sheet pile, the global stability safety factor FOS begins to decrease gradually, and with the increasing of embedded depth, the effect of cantilever length on stability of revetment becomes weaker.