The invention relates to a distillers' grains acid-base modified adsorption material and a preparation process thereof. Raw materials containing distiller's grains are subjected to acid addition, alkali addition, blending, microwave heating, liquid slag separation, washing and drying to prepare the distillers' grains acid-base modified absorption material. The process provided by the invention does not comprise drying of distiller's grains; a separation lotion can be reused; a modification liquid can be used for fermentation preparation of fuel ethanol; and the prepared distillers' grains acid-base modified adsorption material has adsorption removal rate of about 90-99% and adsorption capacity of about 500mg / g on Pb<2+>, Cd<2+>, Hg<2+>, Cr<3+>, Cr<6+>, Ag<+>, Cu<2+> and Zn<2+> in heavy metal wastewater.