The chloride ion permeability of concrete is an important indicator of concrete durability, which affects the service life of water diversion tunnels and other projects. In order to obtain the influence of high ground temperature on the chloride ion diffusion of concrete, the numerical calculation method of nonlinear chloride ion adsorption model and temperature coupling is used based on the experimental results of chloride ion penetration resistance of concrete under different curing temperature conditions. The diffusion law of chloride ion in concrete under different temperature gradient conditions was analyzed. The results show that the chloride ion penetration resistance of concrete at 20~60°C increases with the increase of temperature; the chloride ion penetration resistance of 60~90 °C decreases rapidly with the increase of temperature; Free chlorine ions diffuse non-linearly in concrete over time and the depth increases until it penetrates the concrete; Therefore, the study of the diffusion distribution of chloride ions in concrete can objectively predict the service life of concrete.