To study the effect of mung bean germination on its antioxidant activity. Experimental design mung bean germination for 6 days, the antioxidant content of total phenol, flavonoid, vitamin C, antioxidant ability DPPH clearance rate, –OH clearance rate, total reduction ability were selected as indicators, combined with correlation, significance analysis and other methods to analyze the changes of each indicator. The results showed that content of total phenols and flavones increased first and then decreased, vitamin C increased all the time, and the index of antioxidant capacity increased first and then decreased. The total phenol content reached its maximum on the 4th day of germination, and varied from 0.5612 mg/g to 0.7237 mg/g on the 1st to 4th day, increased by 28.95%. On the 3rd day of germination, the flavonol content reached the highest level. The flavonol content varied from 0.6605 mg/g to 0.6974 mg/g on the 1st to 3rd day, increased by 5.59%. Vitamin C varied from 0.7833 mg/100 g to 7.4500 mg/100 g on the 1st to 6th day. From 1st to 3rd day, DPPH clearance rate, –OH clearance rate and total reduction capacity reached the highest levels of 99.28%, 97.00% and 79.26% respectively, increased by 4.68%, 1.04% and 46.76% respectively.