In order to achieve minimum deformation of optical components and ensure beam quality, temperature control of switchyard mirror box in target area of the laser inertial confinement fusion (ICF) devices is very important. Mathematical and physical models of switchyard box in target area are established. FLUENT software is used to analyze the temperature field inside mirror box and analysis result is consistent with the measured result. The temperature field distribution and stability time inside mirror box impacted by different wind velocities and angles are analyzed, the results show that the greater the speed, the faster the temperature field inside mirror box stabilized. And when wind velocity v is greater than 1.3 m/s, the decrease of stability time is not obvious. Wind angle shows great impact on the steady of temperature inside mirror box and the best value is obtained. When wind velocity v is 1.3 m/s and wind angle θ is 20°, the stability time inside mirror box is the shortest with the value of 77 min. And within 32 min after the blower turned off, the temperature difference between the mirror is in the allowable range, with a maximum of 0.009 K.