A range parameter η exists in the formula for calculating the equivalent rigid joint depth in the design specification,and its different value will lead to the difference of calculation results by several meters,which greatly affects the calculation of superstructure.We apply the finite element analysis to calculate the horizontal displacement of the top of a single pile for the PHC pile,steel pipe pile and cast-in-place pile,which are commonly used in engineering.According to the basic assumptions of material mechanics,we constrain the cantilever beam deflection curve equation with beam end freedom and beam end rotation,and obtain a series of equivalent rigid joint depths of various pile types.Combined with the formula of design specification,we get the η value recommendation and matters needing attention for the equivalent rigid joint depth calculation.The research results can provide references for the calculation of pile foundation structure.