Abstract: The numerical answers of critical edge pressure of subsoil and critical load are calculated by using MATLAB program. Coefficient of earth pressure at rest is not made to be 1 in the program. This numerical method corrects the unreasonable hypothesis of =1 when proposing traditional formulas of subsoil bearing capacity. And the method corrects some calculating mistakes when proposing formulas of subsoil bearing capacity which obtains ≠1 by some scholars. It compensates the limitation of some other calculation formulas when they are be used. And the numerical answers conform to real projects much more. The influences of shear strength indexes on critical load of subsoil are given. Different critical loads which calculated by using different , one is , the other is 1, are compared.