In order to establish a more realistic airdrop kinematics model, the drag direction was presented and the interaction force between cargo and airplane were deduced.Many influence factors such as rigid body good, extraction parachute and the angle of cabin floor were considered in the model.The 0-1 control variables were designed for time-shared control of the cargo at different airdrop phases.The modeling process was simplified, which could simulate the different airdrop modes.A simulation platform for cargo airdrop system was designed, which integrated such functions as airdrop parameter setting, simulation, analysis and display.At last, a quantitative analysis was made to the dynamics response error of the proposed mathematical model and the tradition model through simulation.