Abstract: In order to evaluate the stability of the rock，based on the uncertainties of the influence factors of the rock quality，six main indexes which can indirectly reflect the rock quality were selected by fuzzy mathematics method，and the index system which can affect rock quality was constructed.According to the principle of maximum membership degree，the fuzzy comprehensive evaluation principle is used to evaluate and deal with the six indexes，and the mathematical evaluation model of rock quality is obtained.After the relevant data were gained from the six indexes of rock samples in different parts based on the indoor test result，the model was used to evaluate the rock samples of different parts.The results were compared with the actual situation of the project.The results showed that the evaluation results of the model and the actual situation of the mining area is basically the same.It is proved that the fuzzy comprehensive evaluation model of rock quality is scientific and feasible.