The invention provides a solar-heated drying device. A diffuse reflection plate is arranged on the whole outer surface of a solar water heater. Vacuum heat absorption pipes are evenly arranged on the surface of the diffuse reflection plate from top to bottom. A water inlet and a water outlet are formed in the lower portions of the two corresponding sides of the solar water heater correspondingly. The water inlet communicates with a water source through a cold water pipe. The water outlet communicates with a connector on the upper side of one end of an outer shell through a hot water pipe. The solar-heated drying device can store heat energy so that work can be unceasingly completed under the condition that no illumination exits at night, energy is saved, and the solar-heated drying device is more environment-friendly.