Abstract: The crude caprolactam was obtained by the vapor-phase Beckmann rearrangement. The product was successively refined by distillation, benzene dissolving, water extraction, ion exchange, hydrogenation and triple effect evaporation, similar to the liquid-phase Beckmann purification process. The changes of purity, UV number, color, volatile base number and potassium permanganate absorption values (PM) in each refining step were investigated. The results show that the purity of the refined product is up to 99.950%, PM and color meets the premium grade, the UV number and the volatile base value reaches the first class and the qualified class, respectively.