Abstract: LCTF (Liquid Crystal Tunable Filter) is one of the rapid developing technologies in recent years. LCTF has many advantages, such as high spectral resolution, wide spectral range and light mass, so it is used widely in hyperspectral imaging remote sensor for lunar exploration. Various temperature in Liquid Crystal of LCTF will cause larger deviation of double refractive index, and that will affect the imaging quality of LCTF spectral imager. Working conditions of LCTF imaging spectrometer were analyzed in this paper. With the consideration about LCTF working modes and working temperature requirements, thermal control system was designed for LCTF spectral imager. The simulation results show that the designed thermal control system can meet the design requirements and LCTF spectral imager can get clear image to get ready for lunar exploration.