The invention discloses a closed-cycle recycling method for a solvent in PVC foaming board production. A hot air circulating oven, a surface condenser, a centrifugal fan, a pretreater I, a pretreater II, an adsorber A, an adsorber B, an adsorber C, a compressor, a condenser and a recovered solvent storage tank which are connected in sequence are involved in the method, a filter is arranged at an inlet of the hot air circulating oven, and a heater, a flow guide plate, an air door, an automatic conveying trolley and a main fan are arranged inside the hot air circulating oven. By recycling the organic solvent used in the PVC foaming process and removing the organic solvent remaining in foaming boards, the fire resistance of the foaming boards is guaranteed, and the problem that in present domestic PVC foaming board production processes, organic solvents are difficult to recycle and pollute the environment is solved.