Compared with the model group, the body weight of PCOS rats treated with DNLP was reduced (P < 0.01), the estrous cycle returned to normal, and serum testosterone levels and insulin resistance were also reduced. In addition, the volume of the corpus luteum increases, the number of antral follicles decreases, and the thickness of the granulosa cell layer increases. DNLP treatment also increased the expression levels of PCNA, and inhibited cell apoptosis in PCOS ovarian tissue by regulating apoptosis related proteins Bax, Bcl-2, and caspase-3. The gene discussed is PCNA; the disease is polycystic ovary syndrome.