The reasons for in situ recurrence one year after liver cancer surgery may include the tumor cells are not completely eliminated during the first surgery, which leads to recurrence of tumor cells, and the tumor cells are re-diseased due to the original disease or bad living habits after surgery. 1. The tumor cells are not completely eliminated during the first surgery, which leads to recurrence of tumor cells: because the first surgery can not remove the smaller lesions, but only some larger tumors can be removed, and these small lesions are easy to recur and metastasize, which leads to in-situ recurrence of liver cancer one year later. 2. Post-operative recurrence of tumor cells due to primary disease or bad living habits: patients with irregular treatment of primary disease, bad living habits, heavy drinking and smoking, etc. will lead to recurrence of cancerous cells in the liver. After surgery, patients need to have regular checkups, develop a good living habit, and carry out standardized treatment for the primary disease under the guidance of doctors, so as to keep away from the triggers of liver cancer.