Colorectal cancer is one of the most common malignancies. The liver is the most common site of distant metastasis, and liver metastasis is the leading cause of death in the patients with colorectal cancer. In recent years, the concept of diagnosis and treatment in colorectal liver metastasis (CLM) and the liver surgery techniques developed rapidly, the standardization of clinical practice elevated obviously, and the survival outcomes of more and more patients were significantly improved. Standardization of diagnosis and treatment in CLM comprised overall assessment of patients' condition and local tumor status based on multidisciplinary team collaboration and then institution of treatment strategy. Standardization of CLM diagnosis should be carried out by abdominal enhancement CT, or liver ultrasound to evaluate the hepatic metastasis. As for suspected CLM, serum AFP and liver MRI are recommended. When resectability is assessed, both surgery techniques (procedures, liver preservation, and resectable lesions outside of liver) and oncology items (synchronism, heterochronism, invasion and progression) must be considered. Due to complicated illness and different prognosis, CLM patients should be carefully classified to receive associated treatment. For CLM patients with resectable or potentially resectable lesions, the aim of treatment is to increase the R0 resection rate and survival. For those with unresectable lesions, the aim is to improve tumor-associated symptoms and maintain the quality of life.