Carbonation of concrete and chloride-induced corrosion of steel fiber are two potential threats to the durability of steel fiber reinforced concrete (SFRC). In this study, the properties evolution of SFRC under the coupling effect of carbonation and chloride attack was investigated, and the deterioration mechanism was also explored. Results showed that the compressive strength of SFRC increased during the 360 days under the coupling effect of carbonation and chloride attack. However, the flexural properties exhibited an increasing trend before 120 days, with peak strength and flexural toughness rising by 60.8% and 43.9%, respectively, followed by a subsequent decline, which were lower than initial flexural properties after 360 days. Compared to the single chloride attack, the coupling effect of carbonation and chloride attack accelerated the corrosion process of SFRC. After 360 dry-wet cycles of chlorides, the inner steel fibers within approximately 10 mm from the SFRC surface were severely corroded, while steel fibers at the deeper depths remained uncorroded despite the chlorides ions penetration depth exceeding 40 mm. Furthermore, the deterioration process and potential mechanism of SFRC was elaborated upon, which provides empirical evidence and establishing a theoretical foundation for the development of highly corrosion-resistant SFRC.