Through selecting the index of MSW compost quality and establishing the evaluation grades of index, an evaluation system with the method of fuzzy mathematics has been framed in this paper. Then, based on the assessment of single factor and comprehensive effects of different factors, in this paper, the experimental data are taken for example to evaluate the MSW compost quality. The result shows that this method is successfully applied and also can be used as a simple useful method to the evaluation of MSW compost quality.