The invention relates to the field of film-spreading oil solution, in particular to nimbin film-spreading oil solution which is prepared by mixing nimbin and nim oil in certain proportion and adding an auxiliary material into the mixture. The nimbin film-spreading oil solution is novel, efficient and pollution-free, is safe to human, livestock and fowls, and is difficult for pests to generate drug resistance. The nimbin film-spreading oil solution has the advantages of wide sources of raw materials, high utilization ratio, simple process and low production cost, and is a novel biological pesticide preparation.