The invention discloses a refining method of a pyrethrin crude extract, which comprises the following steps: (1) dewatering and degassing a pyrethrin crude extract raw material through thin film distillation; (2) carrying out molecular distillation on dewatered and degassed liquid to obtain a pyrethrin mixture; (3) mixing the pyrethrin mixture with a weight ratio of 1:2-1:10 with a solvent and agitating at a temperature of 20-60 DEG C; controlling the temperature within 30 DEG C below aero-35 DEG C after uniformly agitating, standing or intermittently mixing, crystallizing and settling; and removing a crystallized matter through suction filtration or centrifugation after settlement for 1-24 hours to obtain yellow transparent solution; (4) concentrating the yellow transparent solution and recovering a solvent to obtain a yellow oily matter, i.e. a pyrethrin fine product. The refining method has the advantages of simple process, high product content and low production cost and is suitable for industrial production.