Generally, IUI can be performed only when the vaginal discharge and cervical mucus cleanliness are checked to be normal. I. Choose the proper timing. One of the keys to improve the success rate of artificial insemination is to choose the exact time of insemination: artificial insemination is most likely to be successful from 48 hours before ovulation to 12 hours after ovulation. 1. Basal body temperature (BBT) measurement: i.e. the body temperature of the organism in the resting state. The basal body temperature measured daily during the menstrual cycle is recorded, drawn as a curve and observed. The basal body temperature is lower during the follicular phase and lowest on the day of ovulation. After ovulation until 1 to 2 days before the next menstruation, or on the day of menstruation, the body temperature returns to normal. 2. Cervical mucus examination: At ovulation, cervical mucus is thin and transparent, and mucus filaments can be elongated up to 10cm or more. After ovulation, the cervical mucus becomes cloudy and sticky, and the degree of stretched silk decreases. Before ovulation, cervical mucus smear can show lamb’s tooth-like crystals. 3.Hormone measurement to predict ovulation: the peak of luteinizing hormone before ovulation can predict the time of ovulation. 4.B ultrasound to monitor follicular development and endometrial thickness. II. Preparation of semen Before husband sperm insemination, the husband should abstain from sex for 3-5 days. The husband should wash his hands and around the penis before sperm retrieval on the same day and use the masturbation method to retrieve sperm, taking care to avoid touching the inner mouth of the sterile, non-toxic sperm retrieval cup to ensure the integrity of sperm retrieval. Send it to the laboratory immediately. After the semen is liquefied, routine semen analysis is performed, including semen volume, liquefaction time, sperm count, motility rate and agglutination, etc. Different methods are selected for preferential treatment according to semen quality. The whole process is carried out inside the ultra-clean table to ensure sterility. Commonly used semen processing methods generally include: washing, upstream, downstream, Percoll gradient centrifugation, micro-Percoll gradient centrifugation, etc. The preferentially selected semen is placed at 37°C and set aside for use. III. Implementation of artificial insemination For artificial insemination by husband, 0.3-0.5 ml of the preferentially processed semen is slowly injected into the uterine cavity by intrauterine insemination method. The whole procedure is strictly aseptic. The patient must lie flat with legs together for 30-60 minutes. Generally, one insemination is performed one day before ovulation and one on the day of ovulation.