Abstract: In order to meet the needs of rapid loading/unloading of air cargos on helicopter and the light weight air transportation, a new type of reloading and tranfer cart made of aluminum alloy material is developed. In this paper, the ABAQUS software is used to establish the finite element models of the main structure, the legs, and the load-sharing panel, and carry out the static strength analysis. The non-uniform settlement of the cart in the process of loading is simulated by regulating the position of a single support leg, and the average structural strength in the process of loading is calculated by mechanical analysis. In addition, according to the strength design value and the standard value of the strength for each substructure, the strength distributions of the material is obtained, and then the failure probability of each structure of the bracket car is calculated. It is shown that the structural strength of the designed lightweight support cart meets the technological requirements, and the failure probability of each substructure all meets the reliability requirements, while the failure probability of the load-sharing panel made of aluminum alloy 3003 is among the highest, indicating a weak link of the support cart system that should be improved in the design.