The invention provides an operation optimization method for a hybrid microgrid system. The operation optimization method comprises the following steps: obtaining the operation cost parameter and production discharge parameter of the hybrid microgrid system; establishing an operation cost model according to the operation cost parameter, and establishing a production discharge model according to theproduction discharge parameter; and solving the operation cost model and the production discharge model respectively by using particle swarm optimization so as to obtain an optimized result accordingto a solved result. According to the method, corresponding modeling is carried out based on the operation cost and production discharge cost of the hybrid microgrid, and the optimal solutions of theoperation cost and production discharge cost are searched, so that the optimized result can accurately command and dispatch the operation of the hybrid microgrid, the discharge of the hybrid microgridcan be reduced effectively while the operation cost is reduced and trouble-free operation of a main grid is guaranteed, so that the method is beneficial for environmental protection.