The invention relates to a regulation and control method of an automatic air compensation device, which consists of a pipeline, a CCD high-speed camera in a cotton spinning different filament eliminating machine, a pneumatic nozzle, an automatic air compensation device, a pneumatic cotton distribution device, automatic switching valves (C and D) on the pneumatic cotton distribution device, a cotton condenser ventilator, a rolling machine, an end surface (A), a plane (B), an air inlet pipe, an air compensation pipe, an air cylinder, a connecting piece, a positioning shaft, a nut and a support rod, wherein the flow velocities of air at each section of the pipeline are respectively (V1, V3 and V4), the air flow velocity at the air compensation port is (V2), the air port is reasonably designed, and conveniently positioned and adjusted, and air can be compensated for a channel effectively in time when the ventilator changes instantly as long as the adjustment is appropriate, so the speed of the cotton flow detection segment of the cotton spinning different filament eliminating machine is always in a stable state, and the impurity relevance ratio of the cotton spinning different filament eliminating machine is increased.