Aiming at the problem that the reduced hammering energy is excessively different from the actual value when driving sloping pile,we analyze the hammering principle and reducing factors of hydraulic pile driving hammer,obtain the factors affecting energy loss of hammering and increase of side friction resistance of pile,deduce the formulas for calculating active energy loss and passive resistance increment under inclined hammering,and compare the calculation results with the engineering practice.The results show that the calculation results of the formula in this paper can better reflect the engineering practice,and can provide references for the similar projects.