Al_x/HKUST-1(x=1/24, 1/12, 1/6, 1/3), one of the bimetallic copper-based organic framework materials, was successfully prepared by the synthetic exchange method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), specific surface area (BET), thermogravimetric analysis (TG), infrared spectra (IR), X-ray photoelectron spectroscopy (XPS), and H₂-temperature programmed reduction (H₂-TPR). The findings indicated that Al_x/HKUST-1 maintained the octahedral morphology of its precursor (HKUST-1). The thermal stability and catalytic reduction ability of HKUST-1 skeleton were improved by doping aluminum (Al³⁺). Al_1/12/HKUST-1 showed the best performance among all samples, with a nitric oxide (NO) conversion rate of 100% at 210 °C (50 °C lower than that of HKUST-1). The valence kind of Al, Cu, and O in Al_1/12/HKUST-1 did not change after the catalytic reaction, but the contents of Al, Cu, and O in different forms changed significantly. The catalytic process of the Al_x/HKUST-1 followed a Langmuir-Hinshelwood mechanism.