This paper makes an in-depth study on the establishment of the thermodynamic model of the new energy vehicle thermal management system test bench. The model can support the refrigeration filling capacity condition, system refrigeration condition, system heating condition, system dehumidification condition and system defrosting condition, and can simulate the filling capacity of new refrigerants such as R134a, HFO, CO2 and 8290. The model can quickly simulate and calculate the dry and wet bulb temperature, component inlet and outlet pressure, air flow, refrigeration capacity and heating capacity of the new energy vehicle thermal management system test-bed under different working conditions.