Enzyme activity and physiological index of rice changed with the stress environment. To clarify the response mechanism of rice enzyme activity and physiological characters to alkaline environment, this study applied six different concentrations of alkaline salt stress to investigate the rice plant’s response to soda alkali stress. The results showed that SOD activity, ASA content and injury flux decreased significantly with the increase of soda concentration, POD activity, MDA content and relative conductivity of rice leaves increased significantly, CAT activity decreased first and then increased, POD and SOD activity had a linear negative correlation. These findings suggest that rice plants grown in alkaline environments, the membrane of rice cells is damaged, which leads to the weakening of the active oxygen scavenging mechanism of disproportionation, and the catalytic active oxygen scavenging mechanism is the main protective mechanism.