The traditional treatment of rectal cancer is surgery, radiotherapy and chemotherapy, although it has certain cure rate and prolonged certain survival period, but due to the existence of complications such as artificial anus, nerve damage, radioactive proctitis and immune function decline, it obviously affects the survival quality of patients, and even some patients still have tumor recurrence. After our clinical practice, it is confirmed that radioactive particle implantation is a good method to treat rectal cancer. Because the particles are directly implanted in the tumor, the killing effect is obvious, and at the same time, because the irradiation is at a close distance, the impact on the surrounding normal tissues is minimal. As long as the indications and operation protocols are strictly controlled, the side effects are minimal and almost no special treatment is needed, and the treatment time is short, only 2 days are needed for observation after the operation, while the anal defecation function is preserved and easily tolerated by patients. Therefore, it is especially suitable for older and weaker patients who do not want to undergo surgical treatment or have recurrence after surgery. Minimally invasive treatment with radioactive particle implantation is a good treatment for rectal cancer and provides new hope for rectal cancer patients.