Abstract: The present invention discloses a coal-to-acetylene plasma reactor having coking inhibition and online decoking functions, comprising a vertically arranged cathode rod, an anode and a circulating cooling water jacket arranged outside the anode, the anode includes from top to bottom an anode of the electric arc operation section for cooperating with the cathode rod to generate an electric arc, and an anode of the reaction section located below the electric arc, the anode is grounded, the inner diameter of the anode of the reaction section is 1.2 to 10 times the inner diameter of the anode of the electric arc operation section, and the junction of the anode of the reaction section and the anode of the electric arc operation section is circumferentially provided with a decoking nozzle that can spray a decoking medium toward the anode of the reaction section.