Important indicators of ovarian cancer immunohistochemistry mainly include: CA125, CK7, ER, PR, Ki67. Immunohistochemistry testing for ovarian cancer helps to clarify the diagnosis, assess the degree of malignancy, and guide the choice of treatment options. CA125 and CK7 are diagnostic indicators, and if these two indicators are positive, ovarian cancer of epithelial origin is considered, which helps to differentiate it from other metastatic malignant tumors, such as gastric cancer. Patients with positive ER and PR suggest that they are effective for endocrine therapy, and some patients who cannot be treated with chemotherapy in advanced stages can consider endocrine therapy to improve their prognosis. Ki67 belongs to the index to evaluate the ability of tumor cell division, the higher this index is, the stronger the division ability is, and the higher the degree of malignancy is. It is often considered that more than 30% of the tumor cells are of high malignant degree. It is recommended that the patient actively cooperate with the doctor’s treatment, so as to avoid delaying the disease.