Abstract: As one of the key components of thermal vacuum environment simulation equipment, the temperature control performance directly affects the working performance of the environment simulator. In order to investigate the influence factors of temperature uniformity of the temperature control base plate and to improve its heat transfer characteristics, the numerical calculation method of Computational Fluid Dynamics （CFD） is used to carry out the fluid-solid coupling heat transfer simulation, based on the heat dissipation requirements of the heat source in the test piece, the simulation analysis is carried out for the two kinds of different flow paths and different thicknesses of the temperature control base plate to study the effect of the geometrical parameter of the temperature control base plate and the fluid flow rate on the temperature control base plate's heat transfer performance and the pressure drop of the fluid. The effect of the geometric parameters of the temperature control base plate and the fluid flow rate on the heat transfer performance and pressure drop of the fluid is investigated. On this basis, steady state experiments were carried out at −70 ℃ and 120 ℃ respectively, and the results show that a larger number of flow paths will lead to an increase in the flow resistance of the heat transfer fluid, which in turn affects the increase in the pressure difference between the inlet and outlet. With the increase of inlet flow rate, the temperature uniformity gradually decreases. After the inlet flow rate is greater than 2.5 m/s, the temperature difference between the inlet and outlet and the temperature uniformity gradually tends to stabilize, and the increase in the inlet and outlet differential pressure tends to become steeper, a larger number of flow paths and an increase in the flow rate can enhance the heat transfer effect of the heat conduction fluid and the inner wall of the tube.