In order to investigate the right dose of exogenous brassinolide on alleviating the compound preservative (the mass ratio of sodium benzoate to potassium sorbate was 2∶3) stress, maize seedling was employed to test its response to various concentration of brassinolide by improved soil culture. The results showed that compound preservative with 10.0 g/L concentration had a significant inhibition on maize seedling, which resulted in seedling emergence delayed, plant dwarfed, chlorophyll content declined, root vigor lowered, and membrane peroxidation exacerbated. However, the resistance of maize seedlings to compound preservative could improve with applied appropriate concentration of brassinolide as well as alleviated its stress. The best concentration of brassinolide to alleviate the stress of compound preservative was 0.12 mg/L.