The invention discloses a liquid ejection device capable of adjusting ejection parameters. The device comprises a centrifugal pump body, an inlet flange pipe, an ejection component, a throat pipe, an incidence cavity casing, a drainage pipeline, an ejection angle adjustment mechanism and an ejection length adjustment mechanism, wherein the centrifugal pump body, the inlet flange pipe, the ejection component and the throat pipe are coaxially connected in sequence; the incidence cavity casing, the drainage pipeline, the ejection angle adjustment mechanism and the ejection length adjustment mechanism are mounted outside the inlet flange pipe; the drainage pipeline comprises a flow adjustment valve, a horizontal drainage pipe and a flexible drainage pipe; the upper part of the centrifugal pump body is connected with a centrifugal pump diffusion pipe; the side part of the centrifugal pump diffusion pipe is connected with one end of the horizontal drainage pipe; the other end of the horizontal drainage pipe is connected with the incidence cavity casing via a flexible drainage pipe; the flow adjustment valve is arranged on the flexible drainage pipe; the incidence cavity casing is connected with the ejection component via the ejection angle adjustment mechanism; and the throat pipe is connected with a pump inlet of the centrifugal pump body via the ejection length adjustment mechanism. According to the liquid ejection device, a distance between ejected fluid and an impeller inlet, ejection flow and an ejection angle of the fluid can be adjusted freely; the generation of a cavitation phenomenon is effectively avoided; and the cavitation resistance of a centrifugal pump is improved.