Abstract: For the problems of high cost，long period and high risk of airdrop test of airborne vehicles，a simulation model of vehicles and cushion airbags was established in the design phase of an airborne vehicle. A simplified vehicle model，an airbag modeland a rigid-flexible coupling model of vehicle and airbag are established using the finite element analysis method，and the landing buffer processes of vehicle airdrop under normal and extreme conditions are simulated and calculated. The vehicle attitude changes during free fall， airbag cushion and rebound from airbag， the impact acceleration characteristics of bottom deck， top deck and turret of vehicle body， and the maximum stress position and maximum value of vehicle body structure under the two working conditions were obtained. The results show that the top deck of vehicle body has the largest impact acceleration，with an average peak value of 11.31 g under normal condition，and the maximum stress meets the design requirements；under extreme condition，the maximum peak impact load appears at the power plant support，and the maximum stress exceeds the design allowable value，for which a partial structural improvement design is required. The research results can provide the quantified load boundary conditions for vehicle structural optimization design，the calculation data for landing buffer process test and test programs，and the theoretical basis for the matching optimization，testing，and improvement of vehicle body and airbag.

Key words: airbornevehicle, dynamicmodelingandsimulation, impactload, landingbufferprocess