With the rapid development of biotechnology, molecular toxicology has shown great advantages in evaluations of drug safety and has drawn more and more attentions, while its application in safety evaluation of grain and oil is still infrequent. Based on the introduction of the traditional detection methods of grain & oil quality and the characteristics of molecular toxicology, the unique advantages of molecular toxicology in the evaluation of grain & oil quality were introduced by a practical example in order to provide reference for the application of molecular toxicology in the field of quality and safety of grain & oil.