The Ag NPs@HKUST-1 composites have been successfully prepared with different loading amounts of silver nanoparticles in HKUST-1 featuring a three-dimensional system of channels constructed by benzene-1,3,5-tri-carboxylate and dimeric cupric units by a simple one-pot hydrothermal method, and characterized by various microscopy and spectroscopy analysis techniques. The average particle size of Ag NPs increased with the increase of the loading amount of Ag NPs. The experimental results showed that the degradation of sulfur mustard (HD) under ambient conditions followed pseudo-first order reaction kinetics. Additionally, the optimized Ag NPs@HKUST-1 (wherein Ag is 16.67 wt%) exhibited the highest degradation efficacy with an equilibrium rate constant and half-life for HD of 0.0450 min(-1) and 15.34 min, respectively. These values were significantly higher than those for pure HKUST-1 with an equilibrium rate constant and half-life for HD of 0.0168 min(-1) and 41.29 min, under the same experimental conditions. Gas chromatography-mass spectrometry (GC-MS) analysis on the product of 2-chloroethylethyl sulfide (2-CEES) degraded by Ag NPs@HKUST-1 showed that 2-hydroxyethyl ethyl sulfide (2-HEES) is the sole product, indicating that the remarkable enhancement of the degradation of HD must be due to the Ag NPs, which can promote hydrolysis of the chemical war agent in the composite.