Complex Linkage design must deal with multiplicate loads. The sensitivity of each load must be analyzed, as well as the load equivalent integration. The main cause of sensitive loads shall be discovered by means of sensitivity analysis, the load equivalent integration ensures design function can be achieved. As the example shows, an aircraft nose landing gear cannot be normally and alternatively extended on some conditions during flight test and iron bird test. The load sensitivity analysis and load equivalent integration method are used to reappear and solve the problem. The application and importance of this method for complex linkage design are showed.