Stage IIa colon cancer may also have liver metastasis after treatment, which may be caused by recurrence, occult liver metastasis existing before treatment, etc. Colon cancer belongs to malignant tumors of digestive tract, according to TNM staging, stage IIa colon cancer refers to the tumor lesions infiltrating the intrinsic muscular layer and reaching the colorectal peripheral tissues, but there is no regional lymph node metastasis and distant metastasis, so it is recommended that patients should undergo radical surgery, and adjuvant radiotherapy is also needed after surgery if necessary. Although stage IIa colorectal cancer can be cured by treatment, recurrence of the disease cannot be ruled out, and it cannot be ruled out that some patients have liver metastasis that cannot be detected by imaging before treatment, so patients may have liver metastasis of malignant tumor cells even after the disease is cured. In addition, liver is the most important target organ for colorectal cancer bloodstream metastasis, and colorectal cancer liver metastasis is one of the key points and difficulties in colorectal cancer treatment. In order to be able to know how the body recovers, no matter which stage of colorectal cancer patients are in, they need to have regular review after treatment, and intervene as early as possible once abnormal new tumor foci are found in the body.