: In order to simulate the settlement of high-rise buildings in silty sand or fine sand with composite piled foundation, according to geological conditions of Yinchuan as background, A modify Mohr-Coulomb strength criterion was used in simulation. From the underground garage to the ground during construction of the layers to calculate settlement of pile foundation, the settlement observation was calibrating when the first floor starting implementation, In order to compare the calculated value and observed value,Calculation on settlement of the underground garage using the method of reduction processing, through the calculated value and the observed value of pile foundation in sandy soil show that this foundation can provide adequate factors of safety for high-rise buildings.