Grain is by far the largest amount of food stored in the world. The early prediction of grain mold (GM) is mainly to be able to detect it in time before its significant growth activity to avoid causing loss of stored grain. Microorganisms are tiny and not visible to the naked eye in the early stage, if microbial colonies can be observed in the grain pile, these parts of the grain often already have serious deterioration, mold metabolism is more hazardous to produce mycotoxins, which has a more adverse impact on the safe storage of grain, in fact, as long as there is the growth of microorganisms such as mold in the grain, even if the colonies of mold are not visible to the naked eye, the grain quality will have significant changes. In order to ensure the quality of grain output, the best way is to prevent GM. In this regard, this paper suggests a model for predicting the probability of GM based on the Naive Bayes(NB) algorithm, cultivating GM samples, and comparing the prediction errors of these three models with the PSO-LSSVM model and ARIMA model to predict the probability of mold in samples, we know that the prediction error(PE) of the NB model is the smallest, which means that the difference between the predicted value of GM and the real value of the model is small, and the accuracy of using this model for prediction is more reliable. The accuracy of the model is more reliable.