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 integrated with power generation unit (PGU), ground source heat pump and energy storage system was constructed. The models about off-design condition of each device were illustrated. On this basis, four operation strategies were 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 were employed as objectives to analyze the operating time, output and performances of the proposed system under off-design condition. The results show that the proposed system has better economy, lower emissions and lower primary energy consumption than the conventional separate system. Under FTL strategy, the operation cost and carbon dioxide emission are the lowest, which are reduced by 32.7% and 45.3%, respectively. Because of the continuous operating, the reduction of primary energy is the most, which is 86.7%. The results can provide some theoretical references for the operation of distributed system.