The invention discloses a nitrogen-sulfur double-doped mesoporous carbon electrode material as well as a preparation method and application thereof. A precursor of the electrode material comprises the following components in percentage by mass: 20%-85% of a template agent, 10%-75% of a nitrogen-containing compound and 5%-50% of a transition metal salt. The preparation method comprises the following steps: dissolving the template agent, the nitrogen-containing compound and the transition metal salt in a solvent, so as to obtain the precursor; carrying out calcination reduction on the precursor to obtain a primary carbonized material; carrying out acid pickling on the primary carbonized material to obtain a nitrogen-containing mesoporous carbon material; carrying out acid pickling and calcination reduction again, so as to obtain the nitrogen-sulfur double-doped mesoporous carbon electrode material. The application of the nitrogen-sulfur double-doped mesoporous carbon electrode material in a supercapacitor comprises the following steps: transferring a mixed solution of the electrode material, acetylene black, a binder and a dispersant to a glassy carbon electrode; carrying out three-electrode system testing in electrolyte solutions of different concentrations by virtue of an electrochemical workstation. The nitrogen-sulfur double-doped mesoporous carbon electrode material is of a hierarchical pore structure, has a high specific surface area and is an excellent supercapacitor material.