Abstract: The suspended water curtain is widely used in foundation pit engineering. GMS is used to simulate the indoor groundwater seepage model test. The numerical simulation results are compared with the test results to verify the reliability of groundwater numerical simulation software. Then on the basis of determining the accuracy of the software, the change rule of groundwater seepage in different shapes of foundation pit under the same insertion depth of suspended water stop curtain are further studied, providing reference for the actual engineering dewatering design. The results show that the numerical simulation is consistent with the actual monitoring of the water inflow outside the pit and the water level change outside the pit; for the foundation pit with different shapes, the increase of the curtain insertion depth has no obvious effect on the water level outside the pit, but under the same curtain insertion depth, the water inflow of the foundation pit with different shapes is quite different, specifically, the water inflow of the square foundation pit is the largest, the rectangle foundation pit is the second, and the water inflow of circular foundation pit is the least.