In order to seek the coordination of energy supply system in economy, security, environmental protection and energy conservation, relying on the "Internet plus", a distributed cooling, heating and power system is proposed integrated with power generation unit (PGU), ground source heat pump and energy storage system in this paper. The models about off-design condition of each device are illustrated. On this basis, four kinds of operation strategy are put forward: following electric load, following thermal load, following hybrid load and following max efficiency of PGU. Then operation cost, carbon dioxide emission and primary energy are employed as objectives to analyze the operating time, output and performances of the proposed system under off-design condition. Results show that the proposed system has better economy, lower emissions and lower primary energy consumption than conventional separate system. Under FTL strategy, the operation cost and carbon dioxide emission are lowest, which reduce by 32.7% and 45.3%, respectively. Because of the continuous operating, the reduction of primary energy is most, which is 86.7%.