The multi-objective fuzzy collaborative optimization model of multi-energy flow system under different operating conditions is established in this paper to solve the (frequently occurred) non-linear working characteristics problem of the devices in that system, where this non-linear problem causes the offset of operation characteristics and design points of those devices. Firstly, a high-order nonlinear model of devices under off-design performance conditions is constructed on the basis of considering renewable energy sources and energy storage systems including electricity storage (ES) and heat storage (HS). Secondly, according to the needs of different engineering application modes, a collaborative optimization model of multi-energy flow system with economic, environment-friendly and energy saving as optimization objectives is proposed, and a multi-objective fuzzy collaborative optimization model is developed based on fuzzy theory. Then, the physical constraints, such as: equipment load rate, start-up time, working hours and off-design performance under consideration, are taken into consideration. Finally, the model is applied and verified by a chosen case study of a multi-energy flow system. The results demonstrate the availability of regarding the proposed multi-objective fuzzy collaborative optimization of multi-energy flow system under off-design performance conditions as the basis of optimal scheduling, collaborative operation, the design of different operation modes and engineering calculation analysis of multi-energy flow system.