Disclosed are a method and a device for real-time mark for a high-energy X-ray dual-energy imaging container inspection system in the radiation imaging field. The method comprises the steps of emitting a first main beam of rays and a first auxiliary beam of rays having a first energy, and a second main beam of rays and a second auxiliary beam of rays having a second energy; causing the first and second main beams of rays transmitting through the article to be inspected; causing the first and second auxiliary beams of rays transmitting through at least one real-time mark material block; collecting values of the first and second main beams of rays that have transmitted through the article to be inspected as dual-energy data; collecting values of the first and second auxiliary beams of rays that have transmitted through the real-time mark material block as adjustment parameters; adjusting the set of classification parameters based on the adjustment parameters; and identifying the substance according to the dual-energy data based on adjusted classification parameters. The method according to the invention simplifies the mark procedure for a substance identification subsystem in a high-energy dual-energy system while improves the stability of the material differentiation result of the system.