Supply air from top to bottom in the room and spray UV coating with spray gun; Paint is attached to the workpiece surface, and excessive suspended paint mist is sucked into the paint mist recovery host by negative pressure at the bottom; Through * * centrifugal collision, dynamic interception and cyclone separation * *, fine paint mist particles are collided and gathered into droplets; The liquid UV paint flows into the storage bucket along the return pipe, and is sent to the spray gun again for use after the paint slag is filtered and solidified by the filter screen; Exhaust gas is discharged after purification, and exhaust gas treatment can be added at the rear end. Then UV ‑ LED curing machine is connected to complete the coating curing process.