In order to explore the force on the spherical hinge on returning spherical pair of the axial piston pump, the mechanical models of the piston and spherical hinge in the oil absorption area and the oil discharge area were established, and the normal force on the spherical hinge was analyzed and calculated.The results show that the maximum force area on the returning spherical pair is distributed in the oil absorption area;the proper inlet pressure can improve the force condition on the returning spherical pair and improve the service life of the pump; the piston in the oil discharge area is relatively affected small, and the maximum normal force on the spherical hinge is about 1/2 of that in the oil absorption area; when the returning spherical pair wear occurs, the force on the piston in the oil absorption area should be more analyzed. The research conclusion has certain guiding significance for the design of the returning spherical pair and the election of the pairing materials