In order to ensure success assembly of the aircraft landing gear, two error sensitivity analysis methodologies was studied. The main landing gears for the aircraft are developed as the prototype. The sensitivity model is established based on the total differential error by the probability method. The 3DCS software was used as the simulation tool. The paper has analyzed the static assembly process for the landing gear, studied the sensitivity of the assemble rings. The results of the two methods were given and they are approximately equivalent. The contribution of the link between the top joint and the rod 2 is 31.7%, the contribution of the link between the foot joint and the rod 1 is 45.3%, they are both very large.