The distribution and convective depth of chloride ions on the concrete surface under the chloride salt erosion environment were investigated, and the convective depth model of chloride ions on the concrete surface was proposed by analyzing the change of the water-influenced depth and chloride ion concentration. Simultaneously, the internal relationships of the chloride ion concentration on the concrete surface and the elevation, distance from the sea and time were also studied. Then, the corresponding spatial and temporal distribution function of chloride ion concentration on concrete surface was established. The results showed that there was a close correlation between the depth of the chloride convection zone of concrete in chloride salt erosion environments and the water-influenced depth in concrete. The relationship between the chloride ion concentration on the concrete surface and the elevation and distance from the sea can all be characterized by the S-curve. The maximum concentration of chloride ions on the concrete surface increased with the increase of time, but its value eventually tended to be a constant. The convective depth model of chloride ions on concrete surface can accurately present the change rule of concrete surface chloride ion concentration in chloride salt environment, which can provide a reference for predicting the distribution of concrete surface chloride ion concentration.