The invention discloses a solid particle bed gas distribution system and gas distribution method. The gas distribution system comprises a pressure stabilizing system, a flow stabilizing system, a gasdistribution system, an injection chamber, a solid particle container and solid particles, according to the invention, through the grading sub-control gas distribution system with a special three-dimensional structure, automatic, continuous, stable and uniform gas distribution and reaction gas supply to a solid particle bed are realized, and the problems of non-uniform gas distribution, blockage,abrasion and the like in the gas distribution process of the solid particle bed at present are solved. Furthermore, by arranging the gas distribution system with the specific three-dimensional structure and a gas distribution ejector, the tail end gas speed of the gas distribution system is ensured, the probability of system blockage is greatly reduced, and particle abrasion of the gas distribution ejector is avoided to the maximum extent. The solid particle bed gas distribution system has the advantages of high automation degree and wide application range, greatly reduces the operation intensity, enhances the reliability of the process flow, and is suitable for gas distribution and reaction gas supply of most solid particle bed layers under harsh conditions of normal pressure, high temperature and high pressure.