The invention belongs to the technical field of photoelectricity, and particularly relates to a high-resolution visible-light medium-wave infrared dual-waveband optical imaging system. The problems that an existing dual-waveband optical system is low in target recognition capability, the size of the system is large, and the system cannot be mounted and used on a small satellite are solved. The system comprises a first reflector, a second reflector and a light splitting element, wherein a through hole is formed in the center of the first reflector, and the system further comprises a visible light lens set, a visible light detector, a medium wave infrared lens set and a medium wave infrared refrigeration type detector, wherein light beam from the object side is divided into a visible light beam and a medium wave infrared light beam through the light splitting element after sequentially passing through the first reflector and the second reflector, it is seen that the light beam reaches the target surface of the visible light detector after being transmitted through the visible light lens set in sequence, the medium wave infrared beam passes through the medium wave infrared lens set and the medium wave infrared lens set in sequence, and the light beam propagation direction is changed by 180 degrees to reach the target surface of the medium wave infrared refrigeration type detector.