In view of the problem that traditional static parameter equivalent circuit model of a supercapacitor cannot effectively reflect its dynamic operating characteristics, a second-order ladder equivalent circuit model including dynamic charge/discharge resistance and capacitance parameters is proposed.The recursive least square method is used for preliminary offline parameter identification of the second-order ladder equivalent circuit model.Then the offline identified model parameters are used as initial values considering the dynamic change of the supercapacitor parameters, and the recursive least square method with forgetting factor is introduced to identify the dynamic parameters of supercapacitor in real-time.Simulation model and experimental test platform of the supercapacitor are established to verify the effectiveness and accuracy of the proposed equivalent circuit model and real-time identification method through comparison of simulation and experimental results.The results show that the second-order ladder equivalent circuit model with dynamic parameters can effectively reflect the dynamic charge/discharge operating characteristics of the supercapacitor.Compared with traditional three branch and second-order ladder equivalent circuit models with static parameters, the proposed model is improved in accuracy by over 2.08% and 3.56%, respectively.