The invention belongs to the technical field of harmful waste disposal, and relates to a waste acid reduction hydraulic power mixing device, the main body structure of which comprises a circulating pump, a reflux pipe, a mixing pipe, a baffle, a sloping panel, iron powder, a choke, a feeding hole, a discharge hole and a reaction tank, wherein the iron powder settles in the middle of the reaction tank in a concentrated way by the guidance of an inclined surface of the sloping panel, the vertically arranged choke is arranged over the middle of the reaction tank and is used for enhancing the jetflow suction force, so that the iron powder is sucked into the mixing pipe along with water flow; the pipeline of the reflux pipe runs through to the outside of the reaction tank, extends to the upperend of the side wall of the reaction tank along the outside of the reaction tank, and is connected with the reaction tank by a pipe, so that deliver waste acid at the upper part of the reaction tankis delivered to the lower port of the choke by the circulating pump, iron powder at the bottom of the reaction tank is driven to flow to the upper port of the mixing pipe by the flow of the waste acid, and the iron powder and the waste acid are sufficiently mixed and react in the ascending process in the mixing pipe; the mainbody structure is simple, the design concept is smart, the use is safe and convenient, and application is environmentally friendly, and the market prospect is wide.