The reasons why thermal imaging systems consume power are analyzed, and a low power consumption design scheme is presented for the thermal imaging systems operating at multiple temperatures. The relation between the re-sponse performance of α-Si mierobolometer detector and its operating temperature is studied by means of formulas of mi-crobolometer detectors noise equivalent temperature difference (NETD) and detectivity. Numerical analysis based on true parameters demonstrates that the detectivity decreases slightly and NETD increases slightly when operating temperature rises, which indicates that a-Si microbolometer detector has approximately uniform response in a wide operating tempera-ture range. According to these analyses, a thermal imaging system operating at multiple temperatures is designed. The power of thermoelectric stabilizer (TEC) is less than 350 raw and NETD is less than 120 mK in the ambient temperature range of -40 ℃ -60℃, which shows that this system not only outputs high-quality images but consumes low power.