Abstract: In recent years, the Chinese government has vigorously promoted the prefabricated buildings, but the high cost of prefabricated construction directly restricts its development. In order to control the cost effectively, this work discusses the cost evaluation of prefabricated construction. The cost risk evaluation index system is established based on four aspects including environment, design, production and other factors. By determining the main influence factors with comprehensive weights, and building fuzzy matter-element model, and combining with matter-element theory, grade evaluation of actual cases are carried out. The corresponding suggestions are put forward according to the results, which will provide a methodological reference for project cost evaluation.