Abstract: Soybean meal was modified by the thermomechanical spiral extrusion method, and then crosslinked with glutaraldehyde to obtain the soybean meal adhesive. The effects of pH, temperature, and glutaraldehyde content on the glue shear strength were investigated, and the properties of the prepared soybean meal adhesive were characterized. The results showed that, when the screw extrusion temperature was kept at 140 ℃, and the reaction pH, temperature, and glutaraldehyde content were 8, 50 ℃ and 1.0% (based on the weight of soybean meal), respectively, the obtained soybean meal glue exhibited 3.92 MPa of dry glue shear strength and 1.41 MPa of wet glue shear strength, which can meet the national standard of Class II plywood. Meanwhile, compared with the unmodified soybean meal glue, the glutaraldehyde-modified soybean meal adhesive possessed significantly improved solid content, viscosity and thermal stability.