This invention discloses a multifunctional energy dissipation and scour prevention device for the downstream of a
sluice gate and its operation method. It includes a flow guiding unit comprising a rotating flow guiding
pier wall, two automatically retractable flow guiding
pier arrays on one side of the rotating flow guiding
pier wall, a
wing wall flow guiding pier jet array on one side of the rotating flow guiding pier wall, and a central retractable flow guiding pier array on one side of the two automatically retractable flow guiding pier arrays; a scour prevention unit comprising a downstream
wing wall of the
sluice gate, and a downstream
stilling basin apron located at the bottom of the downstream
wing wall of the
sluice gate; and a measurement unit comprising an upstream
water level gauge, a downstream
water level gauge on one side of the upstream
water level gauge, an upstream flow velocity measuring device on one side of the upstream water level gauge, and a downstream flow velocity measuring device on one side of the downstream water level gauge. The beneficial effects of this invention are that it solves the scour problem of the riverbed and
bank slopes downstream of the
sluice gate, and improves the overall stability of the downstream area of the
sluice gate.