The invention discloses a natural environment-friendly modified casein glue and a preparation process thereof, aiming to provide a modified preparation using succinic anhydride as a raw material, starch and urea as auxiliary materials, and a trace amount of monoglyceride , calcium chloride, and sodium benzoate are natural environment-friendly modified casein glue prepared as auxiliary agents and a preparation method thereof; the modified preparation succinic anhydride used in the present invention has little side effects and remarkable modification effect, and succinylated casein carboxyl The content is significantly increased, and its solubility and other processing characteristics are significantly improved; acylated casein is used as raw material to prepare adhesives, avoiding the addition of chemical additives, significantly improving the environmental performance of casein adhesives, and satisfying people's health requirements for adhesives. Environmental protection requirements; the prepared casein adhesive has high viscosity and low stringiness, which can meet the industrial requirements for adhesive bonding; the preparation conditions of the modified casein adhesive are mild, the preparation process is simple, and the preparation process is easy to control. Industrialized production and promotion.