The invention discloses a device used for fracture exploitation. The device comprises a cylinder block and a piston rod, one end of the piston rod movably penetrates one end face of the cylinder blockand is connected with a piston located inside the cylinder block, and the other end of the piston rod is connected with the power end of a fracturing pump; a feeding opening and a discharging openingare formed in the cylinder block, a suction valve is arranged above the feeding opening, the cylinder block is communicated with a feeding pipe through the feeding opening, a discharging valve is arranged above the discharging opening, the cylinder block is communicated with a discharging pipe through the discharging opening, and a plurality of first grooves are formed in the inner surface of thecylinder block; limiting pads matched with the first grooves and a plurality of filling pads are further included, the height of the limiting pads is larger than the height of the first grooves, andthe height of the filling pads is equal to the height of the first grooves; and second grooves are formed in the side face, in contact with the cylinder block, of the piston, and balls are arranged inthe second grooves. According to the device, the first grooves, the filling pads, the limiting pads, the second grooves and the balls are applied, and the aims of reducing the output load of the power end of the fracturing pump is achieved.