Due to the pressure of environmental laws and public environment awareness, green supply chain management got a rapid development in recent years. Through the analysis of the connotation of green supply chain, this paper constructs greenness evaluation index system of green supply chain from five aspects. These include environment, energy, resources, recycling and green management level. It uses the combined algorithm of subjective weight and objective weight to determine the indexes' final weight, establishes the fuzzy comprehensive evaluation model, and at last gives an example, which provides a scientific basis for optimizing green supply chain management.