Disclosed is a heat-radiating internal-circulation power generation device, comprising a solar energy tube (5), three high-positioned expansion reservoirs (6-1, 6-2, 6-3), a low-positioned oil storage reservoir (25), three circulation pumps (8-1, 8-2, 8-3), an energy storage tank (7), a constant temperature furnace (12), a condensed water expansion tank (10), a high pressure plunger pump (13), a high pressure atomizing device (14), a steam generator (15), a steam storage tank (18), a steam turbine (19), a power generator (20), a circulating steam duct (21), a steam condenser (22) and a condensed water pipe (23). In the energy storage tank (7), a saline solution is used as an energy storage medium. Complementary heating of heat conductive oil with other multiple energy sources and solar energy is achieved by the constant temperature furnace (12). The steam generator (15) has layers of annular sealing ducts and the heat conductive oil circulated within the system conducts heat to the steam generator (15), such that an atomized moisture flow is instantly converted into high temperature and high pressure steam to arrive at a critical effect. The present device has the advantages of a long service life and easy maintenance, and is applicable in the fields of large-, middle- and small-scale power generation.