Colorectal cancer is one of the most common malignant tumors of digestive tract. In recent years, with the introduction of the concept of precision treatment and the improvement of precision diagnosis technology, scholars have gradually paid attention to Her-2 positive colorectal cancer, which accounts for about 5%, including Her-2 overexpression, ERBB2 gene amplification and mutation. At present, many studies have confirmed the feasibility of targeting Her-2 in colorectal cancer patients with overexpression or amplification of Her-2 that fail to receive standard treatment, but there is no definite and feasible treatment strategy for Her-2 mutant patients. This article reviews the progress in the diagnosis and treatment of Her-2 positive colorectal cancer in recent years.