Abstract: The present application provides a split band-based reversely different light path (RDLP) solar thermal compound device. The device includes, but not limited to: a split band RDLP component, a mid-infrared radiative cooler, and a sunlight converter. The split band RDLP component is disposed above the mid-infrared radiative cooler and the sunlight converter, and is suspended by using a support, so that the split band RDLP component is kept from contacting with the components below, to prevent heat conduction. A cavity is provided between the mid-infrared radiative cooler and the sunlight converter below. The cavity is provided to prevent heat conduction between the two. Such a design implements the simultaneous and efficient use of a solar heat source and a radiative cooling source.