In this work, a facile strategy was proposed to prepare porous single-walled carbon nanotubes (PSWNT) via a green carbon thermal reduction for the first time. The morphology, structure and electrochemical properties of PSWNT were investigated by transmission electron microscopy, X-ray diffraction, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy. Transmission electron microscopy and nitrogen adsorption-desorption investigations indicated the average pore size of PSWNT is about 3 nm. The electrochemical experiments demonstrated that PSWNT possess a relatively large surface area, strong adsorptive ability and excellent electrical conductivity. With the help of the unique porous structure in combination with inherent properties of carbon nanotubes, the PSWNT/GCE-based sensor showed outstanding electrochemical performance for 8-Hydroxy-2'-deoxyguanosine (8-OHdG) with a detection limit of 1.0 nM. Therefore, it is believed that PSWNT is a promising candidate for applications in sensors. Moreover, the influence factors of DNA damage are also studied in detail, and some kinetics parameters are obtained.