Synthetically considering the effects of friction, fit clearance and weight, this study established the theoretical calculation model for the maximum axial bearing capacity of hydraulic cylinders. The influence rule of the frictions at two ends on the axial bearing capacity was studied. It was also simulated by finite element software, which was finally verified by related test data. The results show that the maximum axial bearing capacity calculated by the established theoretical model, compared with the test value, has an error of 13.5%, which indicates that the established theoretical model is reliable. The maximum axial bearing capacity increases with the decrease of the length-to-diameter ratios of piston rod and cylinder, or the increase of friction coefficient. However, excessive friction changes the connection state of the two ends of the hydraulic cylinder, which converts slide state to fixed state and results in abrupt increase of axial bearing capacity. With the decrease of the piston rod and cylinder lengths, or the increase of the piston rod diameter, the impact of friction on the axial bearing capacity increases. However, when the cylinder barrel diameter changes, the impact of friction on the bearing capacity is not changed. This research can provide important reference for the design and performance verification of hydraulic cylinder.