Wood has a multi-scale pore structure, creating conditions for the development of new water purification materials. However, the adsorption capacity of wood for dyes is always limited, so this study combines the unique structure of wood with Ag nanoparticles (NPs) to achieve efficient catalytic reduction of dyes, harnessing the advantages of both. Ag/wood composite filtration materials with different Ag contents were prepared by hydrothermal method and vacuum impregnation. The results showed that with the increase of Ag content, the interaction between metal and wood channels and the degradation performance of Ag/wood composite materials exhibited a volcano-shaped trend. The contact area between Ag NPs and dye molecules plays a key role in the degradation of dye. The load phenomenon and internal flow state were discussed in detail by means of hydrodynamic simulation. Ag0.05/wood composite made silver nanoparticles and dye molecules reach a high balance and reduction degree. Therefore, Ag0.05/wood composites showed the highest catalytic reduction efficiency and great stability during the degradation of dyes, with a degradation efficiency of up to 96.9 %. The novelty of this study lies in the detailed description of the electron transfer process and mechanism of Ag NPs as a relay during MB degradation.