Geostationary orbit satellite-borne optical-electro-mechanical instrument is mounted on the satellite crossing panel.The two-dimensional turntable revolves around the two axes and points to the ground,which aggravates the change of the orbital heat flux.The internal optical device parts bring high heat dissipation,but heat transfer path is complex.It is a challenge for thermal control.Owing to ensure communication quality,high temperature stability and equality are required.According to the work and configuration characteristics of the equipment and the rule of outer space thermal environment,the thermal control system was designed with regionalization method.Some innovative measures,such as three stage temperature control,multi-layer insulation components installation ring,and heat collection and transport channel,are put forward.Temperature distribution were computed with NX TMG software,the results of simulation show that the thermal control system can meet the requirement of attitude-varied terminal,and the thermal design is feasible.