In order to study the distribution and diffusion law of chloride ion in concrete under saturated state, the standard curing of ordinary concrete and high-performance concrete was carried out firstly, and the samples were then placed in chloride tanks filled with NaCl solution, and the chloride ion mass fraction in concrete was obtained. The Matlab was used to draw the pattern of chloride ion diffusion, and the experimental value and model value were compared. The results show that the chloride concentration of NC30 is 51.0% and 63.1% higher than that of NC40 and NC50, and that of HPC30 is 25.2%,47.4% and 51.6% higher than that of HPC40, HPC50 and HPC60, respectively, when the erosion depth is 2.5~17.5 mm.When the water-binder ratio is equal, the chloride ion concentration of NC30 is about 51.6% higher than that of HPC30, the chloride ion concentration of NC40 is about 43.0% higher than that of HPC40, and the chloride ion concentration of NC50 is about 54.8% higher than that of HPC50. The influence of water-binder ratio on chloride ion diffusion of concrete increases with the increase of strength grade. In a certain range, adding admixture is better than reducing the water cement ratio to diminish the diffusion of chloride ion in concrete.