Abstract: In order to improve the heat dissipation performance of the thermostat, the heat dissipation fin of the micronuclide thermostat was taken as the research object, the response surface analysis experiment of the thermostat fin was designed according to the Box-Behnken response surface method. The heat dissipation performance of the thermostat under different combinations of fin structure parameters were simulated and analyzed, and the fin structure parameters with the best heat dissipation performance was explored. The results show that the heat dissipation performance of the thermostat is different under the different structure parameters. The best fin thickness is 1.058 mm, the spacing is 2.014 mm, the length is 43.996 mm, and the distance between the fin and the inner wall is 3.850 mm. After optimization, the maximum heat dissipation temperature of the thermostat is 77.37℃. Compared with the original thermostat, the maximum heat dissipation temperature decreases by 1.09℃, and the heat dissipation performance is improved.