Small and medium-sized ecological weir and method for regulating and controlling fish water flow habitat

The invention discloses a small and medium-sized ecological weir and a method for regulating and controlling a fish water flow habitat. The weir comprises a weir body, gates, gate chambers, guide rails and an intelligent control system; the functions of a biological migration channel and regulating and controlling gates are combined; the connectivity of water bodies on the upstream side and the downstream side of the weir is effectively guaranteed; and meanwhile, the effect of fish habitat communication is achieved. The regulation and control gates are arranged at the biological migration channel and at the gate chambers in a stepped mode, the discharge amount of river channel water flow is controlled in a transverse opening and closing mode, and a plurality of water permeable holes are formed in the gates so as to relieve the impact effect of the water flow on the gates and the weir. The gate chambers are arranged in the weir body, the sizes of the gate chambers are suitable for arrangement of the gates corr