As the composite system of wetland ecology, economy and society is divided into wetland ecological subsystem, wetland economic subsystem and wetland social subsystem, this paper did the research on the measurement of the synergy degree between the three subsystems. First, we built the index system for measuring the order degree of each subsystem by PSR model and calculated the weight of each index. On this basis, this paper built a model for measuring the synergy degree. Then this paper did the empirical research using the data from 29 provinces, and the results showed that: the order degrees in different areas and subsystems are different; the synergy degrees in different areas are different; the wetland composite system in western China is evaluating to be more harmoniously, while in the east it’s evaluating to be less harmoniously and in central China it evaluated from disharmoniously to harmoniously and to disharmoniously.