The invention discloses a purifying method of N-vinyl-Epsilon-caprolactam, aiming to overcome the defects of more process steps, difficult operation control and high requirement for the content of mother liquid in the traditional purifying method. The purifying method comprises the following steps: A. extracting and washing: dissolving N-vinyl-Epsilon-caprolactam reaction liquid to be washed by adding an organic solvent, adding water in an organic system to wash; and B. distilling: distilling the organic solution in the step A at normal pressure to recycle the organic solvent, and carrying out reduced pressure distillation to obtain the N-vinyl-Epsilon-caprolactam with high content. In the purifying method, a distilling method is adopted, most importantly, liquid-liquid extraction is used as a main purifying means in the method, and the reaction liquid is directly treated, thereby omitting the distilling step, ensuring that the method and needed equipment are simpler and suitable for industrial mass production, and saving the production cost; and it is worth mentioning that the caprolactam, the organic solvent and the water are all reused in the whole process.