Internal hemorrhoid is a common kind of benign anal canal disease, treatments of which include traditional treatment, instrumental treatment and surgical treatment, etc. Nowadays, endoscopic sclerotherapy for internal hemorrhoids is gradually becoming the main method. Studies have shown that endoscopic sclerotherapy for internal hemorrhoids has reliable efficacy, higher safety, easy to operate, which is widely used in different levels of medical institutions. The application of transparent cap, sclerosing foam and miniprobe sonography plays a further role in the process of diagnosis and treatment. However, problems such as needle choice, the curative reliability of Ⅲ - Ⅳ hemorrhoids and long time recurrence need to be resolved. The standardized treatment and clinic guideline should be established in near future.