Abstract: Based on stochastic medium theory, the non-linear subsidence model of underground cave surface is proposed, and a novel accelerated hybrid GA(AHGA) was established by setting the DFP method in real-code GA, which is taken as a genetic operator that parallels to the selection, crossover and mutation operators. The advantages of DFP method and GA are considered in this new method, and it not only avoids local minimum values and has a rather high convergence speed, but is also much more applicable, optimal and precise than traditional methods and has been verified by an case history.