Based on special geological conditions of 5201 working face in a mine, method of working resistance was determined as multiple gangue roof load estimation method. Through comparison of calculation principles and results with 3 traditional methods including estimation value and macroscopic damage mechanics method, anti-analytical numerical simulation method and measured statistics method, the conclusion was made that the estimation method was reasonable and effective for estimating resistance of fully mechanized surface in complex structural conditions. Meanwhile, the ZF13000 / 25 / 38 type support bracket used in 5201 working face showed that it could meet support requirements.