Settlement of soil around the foundation pit caused by dewatering, deformation of retaining structure and foundation pit uplift are considered to be the three factors causing ground surface settlement. Using layer-wise summation method to calculate the settlement of surrounding soils caused by dewatering according to the soil settlement mechanism of dewatering. By studying the law of the settlement of the soil caused by the foundation pit excavation, the theoretical formula for the settlement of the soil caused by the foundation pit excavation is deduced. Add up the subsidence caused by the foundation pit precipitation and the settlement caused by the excavation of foundation pit, and revise the results with Modified coefficient, eventually the settlement of soil around the foundation pit is reasonably calculated by the simplified theoretical formula. Through specific engineering verification shows that the derived theory analytical solution is very close to the measured data, the derived theory analytical solution can effectively predict the soil settlement around the foundation pit, thereby this will provides the reliable theory basis for the main body of the construction scheme, to reduce as much as possible the effect on the surrounding environment.