According to German specification BV043/85，the shock spectrum of gear system is gotten. Using the spar element, spring element and tetrahedral element, the dynamic finite element model of entire gear system is established with the software of IDEAS, which includes gears, shafts, bearings and gearbox housing. After the normal mode have been calculated, the vibration velocity, vibration acceleration and dynamic stress of gear system under the double halfsine acceleration shock excitation are simulated. The shock resistance performance of the gear system is analyzed based on the strength criterion.