The remote-excitation polarization-dependent surface enhanced Raman scattering (SERS) induced by plasmonic waveguide is used to investigate the surface catalysis reaction of 4-nitrobenzenethiol converting to p,p′-dimercaptoazobenzene. The propagating surface plasmon polaritons along single-crystalline nanowires can be coupled by the crossed nanowire as nanoantenna for generating massive electromagnetic field enhancement in the nanogap. The remote-excitation SERS spectra in the nanogap reveal the occurrence of a surface catalysis reaction. The time-dependent remote-excitation SERS spectra further confirmed such surface catalysis reaction. This novel sensitive technology could lead to miniaturized photonics and realize high-resolution microscopy/spectroscopy used in the field of remote catalysis reaction.