Abstract: Based on the experiments in references,an approximation to the overturn stablity of geotechnical explosion-proof wall was developed. It was assumed that horizontal blast loading pressure is applied uniformly to the front surface of the wall and the wall rotates around one of its bottom corner as a rigid body. Analytical solutions to the linear differential eqation and formulas of overturn stablity factor were obtained for two blast load models of exponentially decayed load and instantaneous impluse load respectively. The Rung-Kutta method was used for the numerical solutions to the nonlinear differential equation and overturn stablity factor. For two geotechnical explosion-proof walls from references,the results from the present analytical and numerical solutions were compared with experimental results from references,which shows that the theoretical results are in good agreement with experimental ones. The influnces of the blast loading time and the nonlinearity of the differential equation on the overturn stablity factor are negligible,and the overturn stablity factor from the analytical solution of instantaneous impluse load is reliable with the allowable overturn stablity factor 1.1.