IUI indications: 1. infertility caused by cervical factors; 2. infertility caused by male factors mild to moderate oligospermia, weak sperm and poor semen liquefaction; 3. infertility caused by reproductive tract abnormalities and psychological factors such as inability to have intercourse; 4. immune infertility; 5. unexplained infertility or mild to moderate endometriosis, ovulation promotion combined with artificial fertility treatment. Pre-operative preparation and laboratory tests Provided that the three certificates (ID card of both parties, marriage certificate and certificate of prospective fertility) are qualified Female side 1. Medical history taking: including menstrual and marital history, tubal condition, treatment, male partner’s condition, etc. 2. fasting endocrine examination on the 2nd-3rd day of menstruation; 3. 2-5 days after menstruation, a tubal imaging examination should be performed in different rooms, and at least one of the fallopian tubes must be open; 4. fasting blood count, urine count, coagulation series, liver and kidney function, blood sugar, hepatitis B-5, hepatitis C, HIV, syphilis antibody, blood type (not limited by menstrual cycle); male partner: 1. two copies of semen routine report within one year; 2. Five items, hepatitis C, HIV, syphilis antibodies, blood type, etc.