Precipitation system is a common complex system in nature. The interaction and dependent structure of the meteorological factors in the system are of great significance to the establishment of hydrological model. In this study, we propose a framework coupling entropy and copula for analyzing the process correlation of meteorological factors in precipitation system. Based on long time series of daily observational data (1985–2015), we study process interaction between meteorological factors and make better inference for complex system network behavior shifts under changing environment.