Based on the MATLAB simulation technology, a land-based catapult launch system model is established for a certain aircraft. And the influence of catapult launch safety associated with different catapulting parameters(such as final catapulting velocity, catapult takeoff weight and preset rudder deflection etc) can be analyzed by the simulation model. Taking all the influence factors of land-based catapult launch safety into consideration, the research comes up with a basic safety criteria of land-based ejection and the construction of a safe region of catapulting parameters. The research analysis indicates that selecting proper catapulting parameters located in the safe catapulting region can ensure the safety of land-based catapult launch and validate the validity of the basic catapulting safety criteria.