In coastal and inland saline soil environments, reinforced concrete structures are susceptible to coupling erosion of chloride-sulfate, and face more prominent structural durability problems. While experimental and numerical model research is abundant on the erosion process of reinforced concrete caused by either chloride or sulfate alone. Studies on the coupling erosion by chloride-sulfate are relatively limited. Hence, this paper summarizes the research achievements from recent years both domestically and internationally, explores the differences in the mechanism of single salt erosion and chloride-sulfate erosion, and discusses the influence of sulfate ion on the diffusion rate and binding capacity of chloride ion. The existing coupling models for reinforced concrete subjected to chloride-sulfate composite environment are compared, and the construction process of erosion models are elaborated from three aspects: the ionic transport process, chemical reaction, and pore expansion. The currently applied numerical simulation methods are summarized. Finally, the current research on chloride-sulfate coupling erosion of reinforced concrete is reviewed, and an outlook for subsequent research is given.