The reliable equivalent circuit model can accurately simulate the charge and discharge characteristics of power lithium battery, which is the basis of establishing various state estimation methods. The Thevenin model and DP model of lithium battery are established and their parameters are identified online and offline firstly. And then, the model is simulated and verified by the MATLAB/Simulink combined with experimental data. Finally, based on the estimation accuracy and operation speed, the model evaluation method is established, and it is concluded that the DP model can achieve better balance in accuracy and speed compared with the Thevenin model in the online identification process. In the offline identification process, Thevenin model can achieve better balance.