The development of county-level hospitals in China is unbalanced. Due to relatively backward equipment, personnel, departments and fund allocation, the diagnosis and treatment of colorectal cancer cannot be carried out in strict accordance with the international guidelines for diagnosis and treatment of colorectal cancer. However, the county-level hospitals need to serve a large number of people, which is the primary diagnosis unit for most colorectal cancer patients. Therefore, it is very important to develop guidelines for diagnosis and treatment of colorectal cancer in county-level hospitals. Based on the ″China Colorectal Cancer Diagnosis and Treatment Standards″ issued by the national health commission of the People′s Republic of China in 2017, a total of 71 county-level hospitals in eastern, central and western of China have been investigated in terms of colorectal cancer operation, diagnostic equipment, department support, diagnosis and treatment process obstacles, etc. In the guideline, and the changes adapted to county-level hospitals have been made on the basis of the original guideline according to the current situation of county-level hospitals combined with the new progress of diagnosis and treatment after summarizing and analyzing. It is hoped that this edition of the guideline can standardize and improve the level of diagnosis and treatment of colorectal cancer in primary hospitals in China.