The invention discloses a modeling method of a liquid state or semi-liquid state metal battery. The modeling method comprises the following steps: according to a battery impedance spectrum, carrying out fitting, constructing a battery impedance spectrum fitting circuit, and constructing the equivalent circuit model of the battery according to the battery impedance spectrum fitting circuit; adopting symmetrical impulse to carry out a hybrid impulse power performance test on the battery, and obtaining test data used for distinguishing the open-circuit voltage, the resistance and the capacitance parameters of the battery; according to the test data, fitting a function relationship between SOC (State of Charge) and the electrodynamic force, the Ohmic internal resistance, the polarization resistance, the polarization capacitance, the diffusion equivalent resistance and the diffusion equivalent capacitance of the battery, and distinguishing the parameters of the equivalent circuit model; adopting an ampere-hour method to calculate the SOC of the battery; correcting the SOC to obtain a corrected SOC; according to the corrected SOC, correcting the parameters of the equivalent circuit model; and finishing modeling. The modeling method can accurately simulate the external characteristics of the liquid state or semi-liquid state metal battery, and lays a foundation for the charging and discharging management and the subsequent application of the type of novel power grid type energy storage battery including the liquid state or semi-liquid state metal battery.