Lymphatic metastasis of rectal cancer is a serious condition. There are four metastatic routes for rectal cancer, including lymphatic metastasis, hematogenous metastasis, direct infiltration, and implant metastasis. Lymphatic metastasis of rectal cancer has more chances than colon cancer, and the more you go to the lower end, the higher the probability of metastasis. Lymphatic metastasis of rectal cancer is the main way of rectal cancer metastasis, which usually belongs to the middle and late stage in clinical practice. Lymph node metastasis of rectal cancer is one of the most critical factors affecting the postoperative survival of rectal cancer patients. Studies show that the five-year survival rate of patients without lymph node metastasis is 60%-80%, while the five-year survival rate of patients with lymph node metastasis is only 30%. Therefore, lymph nodes in the drainage area should be removed as thoroughly as possible during surgery, and active adjuvant treatment should be carried out after surgery to reduce postoperative recurrence and improve the survival rate of patients.