The staging of rectal cancer is mainly based on TNM staging, and the corresponding overall staging can be derived after T, N and M are determined respectively, i.e., Stage I, Stage II, Stage III and Stage IV. In TNM staging, T represents the situation of tumor primary foci, based on the size of the tumor and the extent of involvement of adjacent tissues. N represents whether the regional lymph nodes are involved and the degree of involvement, if the lymph nodes are not involved, it is indicated by N0, and with the increase of the number of lymph nodes involved, it can be indicated by N1~N2 in turn. M represents the metastasis of the tumor, M0 means that the tumor has not undergone distant metastasis, and M1 means that the tumor has undergone distant metastasis. Stage II is divided into: IIA (T3N0M0), IIB (T4aN0M0), IIC (T4bN0M0); stage II is divided into: IIIA (T1-2N1/1C M0, T1N2aM0), IIIB (T3-4aN1/1CM0, T2-3N2aM0, T1-2N2bM0), IIIC (T4aN2bM0, T3-4aN2aM0, T4bN1-2M0). Patients with different stages of rectal cancer should choose scientific treatment modalities under the guidance of physicians, such as surgical resection, adjuvant radiotherapy and chemotherapy, and actively cooperate with treatment.