In light of the mechanical characteristics of prefabricated integrated pipe gallery under traffic loads， a 3D numerical model of pipe gallery， considering the influence of socket joint and tension of prestressing tendons， is established based on the non-linear interaction between pipe and soil. The numerical model is proved effective through the comparison with the field prototype vehicle load test results. Then， the mechanical properties of longitudinal and interface sections of the integrated pipe gallery under different vehicle loads are investigated. The results show that the longitudinal Mise stress distribution of the pipe gallery is discontinuous at each socket interface. The peak value appears at the middle of the socket interface， and gradually attenuates to both ends. The longitudinal influence range is close to the adjacent two pipe galleries at the loading position. The inner side of the roof， the outer side of the left and right walls and the inner side of the floor at the pipe gallery interface are pulled， while the outer side of the roof， the inner side of the left and right walls and the outer side of the floor are compressed. The concrete at the bottom of side wall and the inner midspan of roof at the socket are the places where the maximum tensile stress occurs， which should be paid attention to. The stress of the pipe gallery structure is positively correlated with the load amplitude， and the change of the loading position has obvious influence on the stress of the bell joint.