Abstract: Aiming at the problem that the size error and hinge clearance error of the driving mechanism of the belt nailing machine will cause the tight press button and the impenetrable belt nail, taking the nail piercing mechanism of the nailing machine as the research object, the influence of the size error and hinge clearance error on the motion output error of the nail piercing mechanism is considered, and the motion error of the mechanism is analyzed. Firstly, the kinematic model of the nail piercing mechanism is established, and the variation law between the end output position of the mechanism and the parameters of each component is obtained based on the continuous contact model and the effective length theory. Secondly, the error model considering size error and hinge clearance error is established, and the mean and variance of motion output error are obtained respectively. Finally, the influence law of each error on the accuracy and reliability of output motion is obtained. By introducing error transfer function, the influence degree of mechanism size error and hinge error on motion output is obtained. The simulation results show that the influence of hinge error on the motion output error is greater than that of rod length error. In the design and assembly stage of the buttoning machine, the clearance error between hinge C and hinge E should be controlled, which can effectively improve the motion output accuracy of the buttoning mechanism. This conclusion has a certain guiding significance for guiding the design of conveyor belt nailing machine and improving the motion accuracy of nailing machine.