Abstract: Modified isocyanate adhesive was used to prepare wheat straw particleboard, the influence of resin content and density on the physical and mechanical properties and thermal stability was studied. The thermal stability and the feature of glued joint section of wheat straw particleboard were analyzed by scanning electron microscopy (SEM) and thermal gravimeter analysis (TGA) so as to explore the mechanism how the physical and mechanical properties were improved. The results showed that the physical performance indexes were improved whereas the thermal stability was reduced along with the increases of resin content. Along with the density increment of the wheat straw particleboard, the physical properties were significantly improved, and the thermal stability was gradually increased. Comprehensively considering the properties of wheat particleboard and the manufacture cost, it was proposed to set 4% as the resin dosage and 08g/cm3 as the density by which technology the major properties of the wheat straw particleboard were optimal, and the physical performance could fully meet the requirements of the national standard.