Zein was known by good film-forming property， but zein film mechanical properties problem affect its effectiveness in practical applications， modification was the effective way to solve the problem. In this paper， acetic acid， lactic acid， succinic acid， malic acid， tartaric acid and citric acid were used to modify zein. When the zein content was 0.1 g/mL； the ethanol volume fraction was 90%； the carboxylic acid amount was added 0.03 g/mL； the alkali-modified solution pH was 5.0； the reaction temperature was 60 ℃； the reaction time was 30 min. The results showed that non-alkali malic acid modified zein film extending rate was （228.17 ± 26.53）%， which increased 154% compared to the control group， but its tensile strength was only （0.70 ± 0.05） MPa. Alkali catalytic citric acid modified zein film tensile strength increased from （7.18 ± 0.54） MPa to （12.73 ± 1.05） MPa， its extension rate was （3.65 ± 0.21）%， which had no significant difference with the control group. The modified zein film had good mechanical properties which not only laid a foundation for its application in food preservation， but also facilitated the extension of China’s corn industry chain and promotes industrial maturity.