Abstract: In order to study the change rule of frost resistance of carbon nanofiber concrete under the action of salt-freeze-thaw cycle, the concrete specimens with four different carbon nanofibers（CNFs） mass admixture（0, 0. 1%, 0. 2%, 0. 3%） were subjected to rapid freeze-thaw cycling test using 3. 5% NaCl solution as the freezing and thawing cycling medium. The fiber modification mechanism was analyzed by scanning electron microscopy, X-ray diffraction, nitrogen adsorption and other microscopic technical means. Moreover, a freeze-thaw damage model was developed to evaluate the damage evolution of carbon nanofiber concrete under salt-freeze-thaw cycling conditions. The results indicated that CNFs could improve the salt-frost resistance of concrete, and the improvement effect was positively correlated with the dosage, and the freezing-resistance grade and durability index were increased by 100% compared with the baseline group at a mass dosage of 0. 3 %. CNFs enhanced the compactness of concrete by bridging cracks, controlling nanoscale cracks, nucleation, and improving pore structure, which in turn improved the salt-frost resistance of concrete.The freeze-thaw damage models established based on different evaluation indexes conform to the Weibull distribution and had R2greater than 0. 9, which can be used for evaluating and predicting the damage of carbon nanofiber concrete under salt-freeze-thaw cycle conditions.