A supercritical carbon dioxide cryogenic treatment device. The device comprises a cryogenic furnace and multiple jet flow pipes (1) which extend into the furnace from the exterior of the cryogenic furnace and are evenly distributed among workpieces (16), the multiple jet flow pipes (1) being all communicated with a main air inlet pipe (5). The device further comprises a first thermocouple (3), a first pressure gage (4), and a first flow meter (6) which are provided in the main air inlet pipe (5), a second thermocouple (7) provided on the center position of the workpiece (16) and a third thermocouple (8) provided on the surface position thereof in a one-to-one correspondence manner, a second pressure gage (13) and a second flow meter (14) separately provided in an exhaust pipe on the top of the cryogenic furnace, and a third pressure gage (18) and a fourth thermocouple (19) separately provided in an internal work area of the cryogenic furnace, wherein the thermocouples (3, 7, 8), the pressure gages (4, 13, 18), and the flow meters (6, 14) are respectively connected to a data acquisition and control system, and the acquisition and control system regulates the flow and pressure of carbon dioxide in the cryogenic furnace to control the speed of a cryogenic process and the temperature of the workpieces (16) according to the temperature, pressure and gas flow data monitored by the thermocouples, pressure gauges, and flow meters.