The invention discloses a design calculation method of a distributed combined cooling heating and power (CCHP) system. The design calculation method of the distributed CCHP system is characterized in that starting equipment and the model of one certain technological process of the distributed CCHP system are selected according to actual needs, and the atmospheric condition at the typical time point when the CCHP system is placed is used for conducting variable working condition correcting; the input/output relation between the equipment is used for conducting equipment connection selecting, meanwhile, the parameter loss of working media in pipeline transmission between the equipment are considered, equipment input working media are used for limiting selecting of equipment models, and variable working condition correcting is conducted on the equipment until the technological process scheme is achieved; a plurality of technological process schemes are combined to form a system scheme, and calculation of operation state and energy supply capacity of the equipment under scheme variable working conditions of the CCHP system is achieved. According to the design calculation method, a plurality of distributed CCHP systems can be flexibly designed, and operation out-of-limit under equipment variable working conditions due to the fact that models are selected according to equipment nominal parameters.