In order to study the influence of underground warehouse ventilation on the temperature field of the grain piles, the temperature field of underground warehouse with the diameter of 25 m and the height of 20.1 m was simulated under 288 h ventilation condition. Based on multi-physical field numerical simulation software COMSOL, the model takes the actual underground warehouse as the background. By adjusting the built-in mass conservation equation, energy conservation equation and momentum conservation equation, the temperature field evoluation of the underground warehouse is analyzed under different inlet boundary pressures and temperatures. The results show that the temperature of vertical ventilation is faster than that of transverse ventilation under the condition of 288 h ventilation of underground warehouse. When increasing the pressures from 50 Pa to 100 Pa, the mean temperature of grain piles was effectively reduced for transverse ventilation and vertical ventilation. When the inlet boundary temperature was lowered from 17 ℃ to 13 ℃, the cooling effect under the same time was significantly improved, whereas the overall grain pile temperature decreased rapidly in the vertical ventilation process. The temperature tended to be stable in the whole underground warehouse after 288 h ventilation.