Colorectal cancer(CRC)is a common malignant tumor of digestive system, and its morbidity and mortality rate is increasing year by year.The liver is the most common site of metastasis and operation therapy is currently the most effective method of metastatic colorectal cancer.The timing of synchronous liver resection has been the subject of debate.Resection strategies include staged resection with colon first approach, staged resection with liver metastases resection first, and simultaneous, with one-stage resection.But factors such as peri-operation period of chemotherapy or some other new methods can affect the timing of the operation.With the continuous progress of the deepening research on colorectal cancer liver metastasis and surgical operation skills for simultaneous liver resection, at present the resection remains largely dependent on the need for neoadjuvant chemotherapy, the surgeons’ judgement of resectability, and patients’ fitness.This lecture reviews and analyzes the recent pregress for liver metastasis of colorectal cancer simultaneous liver resection principles.