By contrasting the main indexes of maize quality standards in China, the United States, Australia and Canada, which are the representative countries in APEC and combined with the actual test results of samples analysis, it is expected to provide a reference for the interconnection of international maize trade standards. The maize quality standards of these four countries all take the unit weight, impurities and imperfect grains (damaged grains) as the main indicators of maize grading. In terms of quota setting, the characteristics of domestic maize circulation are fully considered, and the indicator systems have their own distinctive characteristics based on their own corn production, storage and trade practices. The indicator systems have their own distinctive characteristics, including the definition of maize unit weight, imperfect grains, impurities and other indicators, measuring instruments, measuring methods and quality requirements. When the same samples were tested and judged by different standards, the quality results and quality grades were different, leading to the results being lack of comparability. It is suggested that strengthen communication and coordination among international peers, unify terms and definitions, testing instruments, testing methods should be included to improve trade efficiency, reduce trade costs and promote trade facilitation of maize in the international maize trade and circulation.