A brand-new kind of mid-infrared multi-waveleng th radiation thermometer for the measurement of true temperature and emissivity near room temperature with high signal-to-noise ratio (SNR) was presented. By ap plying blazed grating and refractive-reflected optical system with high image q u ality and throughput, the temperature and emissivity were available simultaneous ly by the MCT semiconductor sensor array and electric system. Inner blackbody so urce was installed to compensate the surrounding temperature drift, and the temp erature of field stop and aperture stop was controlled by a heat pipe to reduce th e influence of stray radiation on temperature measurement. The main structures o f optical and electric systems were described in detail.