In this prospective, randomized controlled trial，the investigators wish to explore the difference of therapeutic effect and prognosis between "hot knife" and "cold knife" in the treatment of uterine adhesion under hysteroscopy.

1. Study Design：This is a prospective, randomized controlled trial.The investigators use hysteroscopy finding as standard reference.

2. Study population 802 patients diagnosed with intrauterine adhesions（IUA）will be prospectively recruited. Before the surgery all patients will undergo preoperative evaluations, including a detailed history of the menstrual pattern,any previous intrauterine surgery, and reproductive history, as well as trans-vaginal ultrasonography.The severity and extent of intrauterine adhesions will be scored according to the ESGE IUA grades.

3. Randomization:

   Randomization was performed electronically using SPSS statistical software version 26.0 (SPSS, Inc., Chicago, IL,USA) by the investigator.802 recruited patients will be randomized to one of the two treatment groups by computer-generated numbers: the control group("hot knife" group) and the experimental group("cold knife" group).

4. Surgical technique:

   • Hysteroscopic surgery will be performed in a standardized manner.The procedure will be performed under general anesthesia. Ultrasonographic guidance will be routinely used.
   • The interference of "cold knife" group (the experimental group) including 401 IUA patients is to perform intrauterine adhesiolysis with scissors, while the interference of "hot knife" group (the control group) is to perform intrauterine adhesiolysis with bipolar electric needle electrode, part of the scar tissue removed by electronic loop when it is necessary.
   • A Foley-catheter filled with 3.0-5.0 ml normal saline will be inserted into the uterus for 5-7 days after surgery.

5. Postoperative treatments

   • All subjects will be treated with oral antibiotics for 5-7 days.
   • All subjects will be treated with Hormone therapy.
   • A second-look hysteroscopy will be carried out in the early proliferative phase 4 weeks after the surgery and an optional third-look hysteroscopy will be carried out 8 weeks after the surgery.

6. Follow up:

   • Follow-up styles: the doctor's outpatient review, telephone, WeChat and so on.
   • Follow-up time:1 month, 2months, 12 months after the operation.
   • Follow up the results of hysteroscopy and the menstrual improvement and pregnancy outcomes at 12 months after the operation.

7. Consent： All subjects will be given a detailed explanation of the study and sufficient time to consider their participation. A written consent form will be signed by the patient and retained in the records.

Inclusion Criteria:

• Indications: fertility desire, periodic pelvic pain;
• Women aged 18-40 years;
• Moderate to severe intrauterine adhesion(ESGE Grade II-IV);
• All enrolled women provided written informed consent and agree to the entire study protocol prior to surgery

Exclusion Criteria:

• Contraindications: such as severe medical diseases, pregnancy status, reproductive tract infection, malignant tumor;
• History of uterine artery embolization;
• Infertility caused by male factors or ovarian dysfunction or premature ovarian failure