In this paper，a method for calculating the side friction of gravel pile interface in gravel stratum un? der the influence of particle shape is proposed. The side friction of a single pile is calculated by using the interface shear function which can describe stress-strain hardening and softening. In order to consider the influence of gravel particle shape on interfacial shear stress-strain behavior，eight kinds of gravel are prepared in this paper. The shape parameters（slenderness ratio，convexity and sphericity）of gravel are obtained by the image processing method. Con? sidering the weight of three shape parameters，an improved calculation method of overall particle regularity is pro? posed. The discrete element model of irregular gravel pile interface shear is established to explore the relationship be? tween the overall regularity of particles and the critical friction angle of interface and the critical state of interface shear. The results show that there is a strong linear relationship between the overall regularity of particles and the critical friction angle，and the overall regularity only changes the intercept of the critical state line. The influence of particle shape is considered in the pile side friction function，and the pile side friction of pile foundation at different depths under vertical load in gravel stratum is solved. The indoor test results are compared with the results obtained by the pile side friction calculation method considering particle shape proposed in this paper，which verifies the ap? plicability and accuracy of the method proposed in this paper.