Combined cooling, heating and power (CCHP) system is an important branch of distributed energy system. It gains much attention for the significant advantages in energy utilization and environmental protection. CCHP is in starting stage,so the economic benefits, environmental benefits, and operation optimization are important for the promotion and application of the system. The main research objects of CCHP system in recent years are classified and discussed, and the research achievements in economic analysis, renewable energy, system optimization made by domestic and foreign scholars are presented in detail.The current status of the study is clarified, and the existing problems in this field are pointed out, which provides reference for research directions in future.