A cheap and facile wet-chemical ‘silver mirror’ reaction approach has been proposed for the silicon nanowires (SiNWs), formed by the metal-assisted wet-chemical etching, decoration with silver nanoparticles (AgNPs). Scanning electron microscopy studies show that AgNPs can be deposited uniformly on the surface of SiNWs by the variation of AgNO3 concentration and reaction time. Adopting the reaction conditions, a homogenous AgNPs shell is formed around the silicon nanowires. The resultant AgNPs@SiNWs nanostructures show significantly (up to 40%) higher light absorption in the near-infrared range (up to 1500 nm) in comparison to SiNWs without AgNPs. This approach opens a new perspectives for a cheap and fast preparation of AgNP shells around SiNWs. Our observation supports that synthesized nanostructures might have promising application potential in near-infrared photodetectors or as photocatalysts.