The low pile cap pier column structure is adopted in the berthing pier structure of a ship lock. According to Technical Code for Building Pile Foundations，the internal force and displacement of pile foundation are calculated according to the calculation method of pile foundation under horizontal load considering the cooperative work of pile cap and foundation pile and the elastic resistance of soil，which is complex and has certain human deviation because of large amount of interpolation and look-up table. We establish the pile foundation，pile cap and soil model by STAAD.PRO software，convert the upper pier column structure and load to stress acting on the pile cap，analyze the internal force and displacement of the pile foundation of low pile cap pier column structure，and compare the code results with the results of engineering examples. The results show that the calculation results of STAAD.PRO are basically consistent with the code results. In the engineering practice，the software can be used to calculate the internal force and displacement of a low pile cap under horizontal load.