According to a technical scheme on the first aspect, the invention provides a drug for treatment of polycystic ovary syndrome (PCOS) and abnormal glucose metabolism coexisting diseases. The drug is characterized by including the following four fatty acid components by mass: 17-22% of palmitic acid, 11-23% of hexadecenoic acid, 22-28% of 9-octadecenoic acid, 13-35% of 9, 12, 15-octatecatrienoic acid, and the balance pharmaceutically acceptable additives or excipients. The components are mixed according to compatibility to be prepared into soft capsules and other oral preparations, so that the insulin receptor substrate (IRS) protein level can be effectively reduced so as to inhibit the glucose way, the insulin receptor active time can be increased and the insulin level can be enhanced, and the insulin sensitivity is increased so as to facilitate the reduction of insulin resistance degree. Thus, the drug can have the functions of improving and recuperating ovary ovulatory dysfunction, i.e. PCOS and abnormal glucose metabolism diseases. Compared with other drugs, the drug has simple components, and belongs to highly effective, safety, and simplified drugs.