Abstract: In order to improve the system efficiency of vanadium redox battery(VRB), based on the composition and working principle of VRB, a hybrid model of vanadium redox battery is established by coupling VRB equivalent circuit model, hydrodynamic model, electrochemical model, and temperature model. The equivalent circuit model shows the electrical relationship of VRB, the hydrodynamic model shows the momentum transfer process of VRB, the electrochemical model shows the mass transfer process of VRB, and the temperature model shows the heat transfer process of VRB. Four models combine the "three transfers and one reverse" with the electrical relationship, and the accuracy of the model is verified by Matlab/Simulink simulation comparison. Based on the hybrid model of VRB which takes into account the temperature change, the coupling relationship between temperature change, flow distribution change and VRB system efficiency is analyzed. The results show that the optimal flow rate is a function of state of charge(SOC) and temperature. The optimal flow rate of each SOC in different periods temperature is obtained by simulation analysis. The optimal flow control strategy in which the temperature change is taken into account is simulated in 5 kW 4 h VRB energy storage system. The simulation results show that the system efficiency increases from 73.7% to 76.4%.