Mycotoxins are toxic secondary metabolites produced by fungi, and among the most harmful are aflatoxin, ochratoxin A, trichothecenes, zearalenone, fumonision, ergot alkaloid and so on. The establishment of the limit standard for mycotoxins is the main measure for the primary prevention of mycotoxins. Through the comparison and analysis of CAC,European Union, the United States and China's grain mycotoxins limit standards, this study has found out the existing gaps in China's current national food safety standards concerning the mycotoxins pollution index of grains, and provided references for the revision of China's grain mycotoxins limit standards.