The invention relates to a sealing device of a high-temperature and high-pressure corrosion electrochemical working electrode and a use method. A kettle cover top end pressing nut is connected with akettle cover top end pressing bolt through threads; an outside-kettle truncated-cone sealing part is squeezed, sealing and insulation between a wire column sleeved with a polytetrafluoroethylene heat-shrinkable sleeve and a high-pressure kettle cover are realized; an electrode block is embedded into an electrode sealing sleeve; sealing between the electrode block and the electrode sealing sleeve is realized through an interference fit mode; an inner threaded hole is machined in the center of the upper end of the electrode block and is electrically connected with the lower end of the wire column through threads; after the lower end of an inside-kettle pressing bolt is connected with the upper end of the electrode sealing sleeve through threads, an inside-kettle pressing nut is connected with the upper end of the inside-kettle pressing bolt through threads; and an inside-kettle truncated-cone sealing part is squeezed, so that the sealing of the inside-kettle wire column is realized. Withthe device adopted, the overall sealing of the high-temperature and high-pressure corrosion electrochemical working electrode and the connecting wire is realized.