The invention discloses an energy transition system applicable to a multi-injection integrated comb-type slow wave structure, and applied to the technical field of vacuum electronics. With regard to the problem of relatively large transmission loss of an existing energy transmission system, the energy transition system comprises a plurality of lines of metal posts longitudinally distributed in a period p, wherein the heights of each line of metal posts are reduced along a longitudinal direction, top ends of the metal posts are curved surfaces, the curved surfaces and a part of a curve line formed by height change of the line of metal posts at positions of the metal posts are coincided, the energy transition system also comprises waveguide structures wrapping the metal posts, and the widthsof the waveguide structures are increased along a height reduction direction of each line of metal posts. By the energy transition system, energy can be coupled to the slow wave structure very well,and meanwhile, amplified energy is output very well.