The chloride ion binding ability of cement-based materials mainly depends on the content and stability of hydrate calcium silicate (C-S-H) gel and Friedel’s salt, and the high content and the great stability of both are benefit to improve the chloride ion binding ability. The influences of various factors, such as cement type, mineral admixture type, temperature, chloride ion concentration, cation type, sulfate erosion and carbonization should be considered in the analysis of the chloride ion binding ability of cement-based materials. They will directly affect the production of C-S-H gel and Friedel’s salt, or indirectly affect the pH value and ion concentration of pore fluid to change the stability of C-S-H gel and Friedel’s salt, thus affecting their physical adsorption ability and chemical binding ability, and promoting the recombination and release of chloride ions, eventually, causing significant change in chloride ions binding ability. In this paper, the changes of C-S-H gel and Friedel’s salt content and stability in cement-based materials under the above factors, as well as their influences on chloride ion binding ability were reviewed, and some suggestions for future research were put forward.