Abstract: To study the mechanical behavior of carbon fiber reinforced concrete (CFRC) further, this paper, based on the experiment and related documents, studies the effects of the dosage of short carbon fiber on the compressive strength of concrete cube test, and obtain the optimum dosage of carbon fiber. At the same time, the whole process of compression failure of the CFRC test tube is analyzed, and the difference between the crack appearance and development of a CFRC test tube under different dosages is compared. Based on the failure modes of plain concrete test blocks, the failure modes of the CFRC test tube are described, and according to the curve of deformation - load under different dosages, it is shown that carbon fiber can effectively improve the failure deformation and compressive strength of concrete.