With beer production waste brewer's grains (BSG) as the raw material, through polyethylenimine (PEI) modified and glutaraldehyde (GA) cross-linking process for preparing the modified brewer's grains biosorbents. The simulation of Cr (VI) wastewater as treatment object, through the optimization of synthesis conditions of Cr (VI), the optimal synthesis process was obtained. The results showed, 4 g BSG and 100 mL 4% PEI methanol solution were placed in 250 mL conical flask at room temperature, shaking for 24 h. After the mixture,shifted to 200 mL l.5% GA solution directly, magnetic stirring for half an hour, the modified results of brewer's grain was best. Under the optimal conditions, the average of adsorption rate was 98.82% and adsorption capacity was 45.31 mg/g. The modified brewer's grains of amine surfactant modified is a promising treatment of chromium wastewater biological materials.