Abstract: Laser communication equipment, with large communication capacity and high-speed transmission, designed for advanced optical communication, has broad application prospects. Owing to ensure communication quality, high temperature stability and equality are required, and outside satellite parts are running in two dimensions to obtain signals in a wider range, bring challenge to thermal control. The design project was based on work characteristic of the equipment and the rule of outer space thermal environment, and a way to thermal control was proposed. Passive method and active method were carried for thermal design, and thermal design of running units, large power units cooling, radiators design, and precision temperature control design, four aspects were presented. According to the state of thermal design, a thermal balance experiment was investigated under low and hot cases, and the results prove the thermal design correct, and bring a way to thermal control for the equipment with high heat flux and running parts.