Earth pressure is closely related with the displacement.In terms of the calculation of earth pressure behind concrete block quay with relieving slab,the code adopted active earth pressure theory is not completely accurate.According to the structural characteristics of quay,we analyze the displacement characteristics of quay wall with good foundation conditions and thin rubble bed and amends the earth pressure calculating method in the code.Based on certain project,we use the numerical analysis method to simulate the displacement and earth pressure of quay wall,compare the results to that of code method.The results show that the correction coefficient can be 1.84 at the bottom of quay wall and 1.34 at the relieving slab,thus it can provide reference for earth pressure calculation of similar project.