SnO2 nanooctahedron with {221} high-index facet (HIF) was synthesized by a simple hydrothermal method, and was firstly employed to sensitive electrochemical sensing of a typical organic pollutant, 1-naphthol (1-NAP). The constructed HIF SnO2 modified glassy carbon electrode (HIF SnO2/GCE) possessed advantages of large effective electrode area, high electron transfer rate, and low charge transfer resistance. These improved electrochemical properties allowed the high electrocatalytic performance, high effective active sites and high adsorption capacity of 1-NAP on HIF SnO2/GCE. Cyclic voltammetry (CV) results showed that the electrochemical oxidation of 1-NAP obeyed a two-electron transfer process and the electrode reaction was under diffusion control on HIF SnO2/GCE. By adopting differential pulse voltammetry (DPV), electrochemical detection of 1-NAP was conducted on HIF SnO2/GCE with a limit of detection as low as 5nM, which was relatively low compared to the literatures. The electrode also illustrated good stability in comparison with those reported value. Satisfactory results were obtained with average recoveries in the range of 99.7–103.6% in the real water sample detection. A promising device for the electrochemical detection of 1-NAP with high sensitivity has therefore been provided.