The invention provides an automatic sediment division and ejection structure with a headwork annular irregular section. The automatic sediment division and ejection structure is composed of a rectangular section, a water inlet, a connecting section, an irregular section, a top plate, an outside plate, an inside plate, a base plate, a sediment collection slot, a trapezoidal section, a sediment discard section I, a sediment discard port, a major diameter vertical barrel, a barrel top cap, a barrel bottom plate, a sediment discard section II, an output section, a diversion canal and a communication pore. The automatic sediment division and ejection structure with the headwork annular irregular section is used for sediment division, large space is not required for sedimentation, and the clearing and transport of sediment are not required; water flow with high sediment concentration can be automatically returned to an original river channel in the sediment division process, and the site, manpower and cost are saved; the sediment ejection effect is good; and the structure can also be buried underground under the proper conditions, so that a ground position is not occupied.