A deep foundation pit project of Beijing is adjacent to the operating metro line 10,the distance of a subway tunnel lining segment recently distance is 5.0 m,in order to ensure the safety of subway operation,orbit requirements caused by foundation pit excavation displacement is less than 3mm.To solve these problems and according to the planned excavation engineering itself characteristics and the surrounding environment and hydrogeology condition,deep foundation pit supporting choose the upper for composite soil nail wall and lower as the underground continuous wall.This paper use li-zheng deep foundation pit software to calculate internal force and displacement of underground continuous wall,surface settlement,and carries on the overall stability,resistance to overturning and piping resistance calculation.Calculation results conform to the requirements of the specification.The field monitoring results show that the slope displacement is small,the rail displacement control within3 mm,the total scheme is reasonable in the economy and feasible in the technology.