Predicting fiber-bridging constitutive law is conducive to the rational design of strain-hardening cementitious composites (SHCCs). However, non-uniform carbonation along depths and fiber-to-matrix interface debonding and healing may significantly affect fiber-bridging behavior, which is seldom considered in current models. Therefore, a new micromechanics-based analytical model quantifying the carbonation-induced depth dependency and the healing-induced interfacial enhancement is developed. Particularly, to quantify the carbonation effect, the quantitative relationships between the interfacial properties (Gd, τ0, and β) and depth y are characterized by Fick’s Law of diffusion. To quantify the interface debonding and healing, the debonding crack lengths are calculated based on preloading level; new interfacial properties (Gd’, τ0′, and β’) are assigned to the debonded-and-healed interface segment; complex two-way fiber pullout scenarios during reloading are determined based on thorough classification. This new model is validated by the tensile test results of SHCCs with pristine and SiO2-coated PVA fibers under monotonic loading and reloading. The modeling results can reflect the multiple peculiar phenomena in SHCCs service, i.e., the overestimation of fiber-bridging strength of partially carbonated MgO cementitious matrix, the healing-induced fiber-bridging tensile strength enhancement, and the coating-induced higher PVA fiber-bridging recovery.