The invention discloses a multi-energy flow system optimization operation method considering the transient heat transfer characteristics of a regional heat network. The method includes the following steps that: step 1) a regional heat network transient heat transfer characteristic model considering a water return pipe network topological structure, a pipe section temperature change dynamic processand a pipe section transmission delay is established based on a graph theory, wherein the model mainly comprises six aspects, namely, a heat source characteristic a heat load characteristic, node flow balance, a node power fusion characteristic, a pipe section heat transfer characteristic and a pipe section transient/steady heat transfer characteristic; and step 2) a multi-energy flow system operation optimization model is established, with the lowest total operating cost of a system in the next 4 hours adopted as an objective function, on the basis of operational constraints that the systemshould meet, the real-time output of each device in the multi-energy flow system, the real-time supply and return water temperature of each heat source of the heat network, and the like, are realized,and the scheduling and optimized operation of the system can be realized. According to the method of the invention, the transient heat transfer characteristics of the regional heat network are considered, so that the optimal operating state of the multi-energy flow system is more consistent with the actual operating state of the system.