Taking paddy as the research object, the integrated temperature and humidity sensors was used to carry out monitoring at different condensation prone locations by simulation of the actual granary. The temperature and relative humidity of different positions of grain stack from winter to summer were measured. Then the cloud map of the temperature field and humidity field of the paddy pile were drawn using Matrix Laboratory simulation software (abbreviated as MATLAB) to analyze the distribution of temperature and humidity fields of paddy. Based on the model of grain equilibrium absolute humidity and dew point temperature (CAE model), the different states (equilibrium state, saturation state, adsorption state or desorption state) of the dangerous point of rice pile were calculated, and the change rules were explored. The results of this paper will provide a theoretical basis for reducing grain storage loss and realizing grain storage safety.