For the problem that fitting model is fixed and precision is low of traditional air-to-air missile launch envelops fitting method, an air-to-air missile launch envelops fitting method based on genetic programming was proposed. Firstly, an air-to-air missile launch envelops fitting model based on genetic programming was established. Secondly, the air-to-air missile launch envelops was fitted by genetic programming algorithm so as to get polynomial fitting model. Finally, regression analysis on the polynomial model was performed by nonlinear regression method in order to update the model coefficient and get the final air-to-air missile launch envelops fitting polynomial. The simulation results show that this algorithm is higher in precision than traditional polynomial fitting algorithm.