The invention provides a fluid measurement device. The device comprises a barrel-shaped reducing plate, an outer barrel arranged on the outer side of the barrel-shaped reducing plate, a sealing cover, a hook and a connection piece, wherein the barrel-shaped reducing plate can slide in the axial direction of the outer barrel relative to the outer barrel; an opening is formed in the barrel wall of the outer barrel; the hook is arranged at the opening position on the outer wall of the barrel-shaped reducing plate; the sealing cover is placed at the opening position and arranged on the outer wall of the outer barrel; a controller is arranged in a direction where the sealing cover faces a liquid inlet of the outer barrel; a force measurement connection point is arranged in a direction where the controller faces the sealing cover; the hook is connected with the force measurement connection point through the connection piece. In case of fluid passing through, measurement of impact force through the controller can be realized; when the controller is switched on, an input fluid flow can be received to determine the fluid density according to a first preset relation; furthermore, the input fluid density can be received to determine the fluid flow according to a second preset relation. The device is simple and feasible and is favorable for being popularized industrially.