As pointed out in this paper that, for a common building material, it is relatively difficult to judge its green degree in comparison with that for a special function material because the judgment factors are comprehensive. The relevant factors which affect the greenness index such as physic expenditure, pollution, economic are analyzed and all influential factors are discussed. For the common building materials, their different inter-restrain factors are divided in administrative level and the weight of factors is determined according to the AHP theory. Meanwhile, the assessment scale and criteria for the factors, and the grading standard for the material green degrees are given in the paper. Based on the fuzzy comprehensive evaluation theory, a green degree evaluation model is established. Finally, the reasonability of the model is testified with the instances introduced in the paper.