Abstract: Abstract: Nowadays, the "three-formaldehyde" adhesives are faced with more and more outstanding problem since resources shortage and the threat of serious environmental pollution to human beings are aggravating. In order to reduce usage of formaldehyde adhesives in plywood, the soybean adhesive is gaining increasing attention because of its reproducibility and pollution-free feature. However, chemical modified soybean adhesive can not meet the demands of the woody adhesive industry market because of lower adhesive strength and water resistance, and pollution property. In this study, in order to enhance utilization value of soybean protein and develop environment-friendly woody adhesive, a new approach for improving the adhesion performance of modified soybean protein adhesive has been studied. The modified soybean protein adhesive was prepared as a new kind of waterproof adhesive to make plywood. For modified adhesive, soybean protein isolate (SPI) was used as main raw bonding material, and water resistance and bonding strength of modified soybean protein adhesive were enhanced by adding basalt fiber (BF). Hence, mechanical properties, rheological properties and morphological structure of the modified soybean adhesives were analyzed to determine the water resistance, and at the same time, relevant bonding mechanism was discussed by Fourier transform infrared spectrometer (FTIR) and Differential scanning calorimetry (DSC). The results revealed the bonding strength with drying and wetting has been increasing with the gradual improvement of BF dosage. During the test, the measured drying bonding strength value of BF/SPI-5% (the mass of BF was 5% of that of SPI) was 2.15 MPa, while the wetting bonding strength was 0.92 MPa. The measurement of wetting bonding strength referred to the GB/T 17657-2013 and the wetting bonding strength could be as high as 1.05 MPa, while the wood compression rate was only 14.92%, which was confirmed by the pilot-scale experimental research, and the results further verify the BF/SPI modification adhesive has a good stability and practicability too. It was found that the shear elasticity was increased according to the result of the rheological behavior. FTIR analysis showed that a new compound structure could be formed with the interaction between BF and soybean protein molecule, and this consequence was confirmed by DSC. And adding small amount of BF led to relatively stable continuous phase in the soybean protein adhesive matrix, as shown in scanning electron microscope (SEM) images. Experimental results confirm that lower dosage BF is beneficial for increasing tack-up reticular structure, which can block up water immersion effectively, and thus greatly improve the bonding strength. In addition, the synthesis process of modified soybean protein adhesive does not need higher temperature. What is more, it has small energy consumption, no waste water, no waste gas, and no waste residue discharge, which are perfectly in accordance with national industrial policy. In conclusion, the research can provide a reference for BF/SPIA application in plywood industry and scientific basis for accelerating the development of environment-friendly woody adhesive.