A large number of uniform cobalt sulfur nitrogen doped carbon nanotubes were obtained by calcining the mixture of cobalt thiocyanate and melamine. The cobalt sulfur nitrogen doped carbon nanotubes were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope and Raman spectrometer. The results show that the carbon nanotubes have regular bamboo-like structure and the Co NPs are encapsulated in the tips of carbon nanotubes. In addition, cobalt, sulfur, nitrogen atoms are doped in carbon nanotubes successfully. The electrochemical test results show that the cobalt sulfur nitrogen doped carbon nanotubes have excellent catalytic activity of oxygen reduction in O₂ saturated 0.1 mol/L KOH. The positive onset potential is -0.12 V, half-wave potential is -0.16 V, and diffusion-limiting current density is -5.62 mA·cm⁻². The synthesis method is simple and feasible, which provides reference value for preparing non-noble metal-based oxygen reduction electrocatalyst.