Disclosed is a supercritical-state cleaning system, comprising a cleaning chamber (4), a gas booster apparatus (11), a first heating apparatus (5), and a carbon dioxide supply apparatus. The cleaning chamber (4) is separately connected to the first heating apparatus (5) and the carbon dioxide supply apparatus. A vacuum pump set (1) is connected to the cleaning chamber (4). Compared with the prior art, in the Invention, air introduced when a workpiece enters a cleaning chamber is completely removed, so as to prevent mixing of CO2 and air, thereby improving a cleaning effect.