A novel phosphate binder was prepared with homemade aluminum dihydrogen phosphate as a matrix and nano-Al2O3, Si powder and low-temperature fused glass powder (Zn-B-Si-Al-R) as fillers to enhance the high-temperature resistance of phosphate adhesives. The interface reaction mechanism was analyzed. The results show that the high-temperature tensile strength of the adhesive is 5.28 MPa at 500 ℃, and the mass loss is only 7.8% when the additions of Fe2O3, ZrO2 and CuO are 5% (in mass), 10% and 15%, respectively. From room temperature to 500 ℃, the coefficient of thermal expansion of the adhesive matches well with the stainless steel substrate, and the difference is less than 1.5×10-6 K-1. Meanwhile, the discrepancy of electric potentials promotes the ions exchange of Fe and Cu, forming the composition gradient layer at the interface, which effectively relieves the thermal stress caused by thermal mismatch and improves the bond strength of the adhesive at a high temperature.