The kinematic accuracy of the locking mechanism is critical to the safety of aviation aircraft. Because of affected by a variety of error factors, every component’s transmission size of locking mechanism should produce deformation and error.It should lead failure and produce major safety accidents. In order to analyze its kinematic accuracy effectively, the kinematic accuracy model of locking mechanism was built based on component’s size error through adopting the method of loop increment.The visual analysis software of kinematic accuracy for locking mechanism was developed. The kinematic accuracy of locking mechanism was simulated.The results show that the projection components of E, F in the X axis andY axis and G in the X axis direction have the greatest influence on the motion accuracy of the hook in the same errors. Therefore, in the process of optimal design, the five variables should be focused on. The developed software can be effectively used to analyze the motion accuracy of the lock mechanism for aircraft, the motion error and force transfer direction of the lock mechanism are truly reflected in the actual work. At the same time, it provides theoretical basis for optimization design of lock mechanism.