The self-leveling device of this carding machine employs an open-loop control method. It adjusts the feeding speed based on the average data from two thickness sensors on the feed roller, enabling rapid tracking of changes in the cotton layer and reducing the unevenness of the cotton sliver. Beneath the feed plate, there are two detection mechanisms that convert changes in cotton layer thickness into electrical signals via displacement sensors and transmit them to the controller. After various digital computations based on the cotton layer thickness, the signals are sent to the actuator to control the speed of the feed motor, thereby adjusting the amount of cotton fed into the carding machine to achieve uniform sliver weight. The actuator utilizes frequency conversion technology, with the inverter controlling the feed motor to match the high-speed rotation of the feed roller. This system offers advantages such as high control precision, rapid response, minimal static error, and excellent stability.