Supercritical waterless dyeing kettle, dyeing system and dyeing method

A supercritical waterless dyeing kettle comprises a kettle body, a feeding pipe, a discharging pipe and a heat preservation sleeve unit arranged on the kettle body. The heat preservation sleeve unit comprises a sleeve body which is arranged on the outer side of the kettle body and is in sealing connection with the outer wall of the kettle body, an air inlet pipe arranged at one side end of the sleeve body, an air outlet pipe arranged at the other side end of the sleeve body, and a control valve arranged on the air inlet pipe; the heat preservation adjusting piece is arranged between the inner wall of the sleeve body and the outer wall of the kettle body. Through the arrangement of the heat preservation sleeve unit, not only is the preheating effect on dye achieved, so that the dyeing uniformity and stability in the kettle body are improved, the dyeing efficiency is improved, the dyeing quality is improved, but also the heating or heat preservation effect on the kettle body can be flexibly switched according t