The present invention discloses a multi-cavity optical sensing and thermopile infrared sensing system, which comprises an optical sensing part, a dielectric layer, a plurality of optical cavities, and a plurality of thermocouples. The dielectric layer covers on the top of the optical sensing part. The optical cavities are formed by a plurality of metal reflectors inside the dielectric layer. The thermocouples are laterally disposed near the bottom of the dielectric layer. In addition, a low temperature region is formed in an area which is the overlapping of vertical projections of such thermocouples and the optical sensing part; a high temperature region is formed by the overlapping of vertical projections of such thermocouples, but without the overlaying which belongs to the vertical projection of the optical sensing part. Therefore, the system can sense the ambient light brightness, color conditions and human blackbody infrared signals within the range of 8-12 micrometers wavelength.