To provide a mooring floating type hydraulic power generation system for generating electric power by maintaining a mooring floating state, while easily and efficiently removing dust, while coping with a change in the water depth and a flow speed in a flow passage.

A mooring floating type hydraulic power generation system includes a floating body plate having a projection shape in the upstream direction of flowing water and having one or more of through-holes or through-grooves, a water turbine supported by and arranged on the floating body plate, a generator arranged on one side top surface of the floating body plate and connected to a water turbine shaft via a speed governor, an electric power converting device and a control device arranged in a symmetric position to the generator, and a dust removing screen arranged in an upstream side projection part of the floating body plate, and the floating body plate wholly mounted with a power generation system constituting apparatus generates electric power while maintaining the mooring floating state of keeping a horizontal attitude to a shaft orthogonal to a flow and being in parallel or inclining in the water turbine existing downstream direction to a shaft along the flow. The system is moored by the through-hole and a mooring column in the floating body plate, and can hydraulically generate the electric power with high efficiency since components are cooled by the flowing water.