The invention discloses an autoclave system used for a high-temperature high-pressure steam oxidation corrosion test. The system comprises a heating device, a temperature control device, a pressure measuring device and a working kettle. The working kettle consists of a kettle body, a kettle chamber and a kettle cover, with the kettle body connected to the kettle cover. The autoclave system also includes a pressure stabilizing kettle used for stabilizing the working kettle pressure and a connecting cylinder used for connecting the working kettle and the pressure stabilizing kettle. The pressure stabilizing kettle and the working kettle have the same structure, and are also provided with kettle bodies, kettle chambers and kettle covers. The connecting cylinder is provided with a through connecting channel along the length direction, and the cylinder body of the connecting cylinder is also equipped with a vent valve for controlling the flow of the connecting channel, one end of which is communicated with the kettle chamber of the working kettle and the other end of which is communicated with the kettle chamber of the pressure stabilizing kettle. The kettle covers of the working kettle and the pressure stabilizing kettle are both provided with deflation valves, and the kettle cover of the pressure stabilizing kettle is provided with a water injecting valve. The autoclave system ofthe invention has good sealing performance and can maintain stable pressure in the working kettle.