Multi-stage ore crushing and screening device

The utility model discloses a multistage ore crushing and screening device, which belongs to the field of constructional engineering equipment and comprises a frame, a feeding bin is arranged at the top end of the frame, and a pair of primary crushing rollers is mounted in the frame through a rotating shaft. The rotating shafts at one ends of the pair of primary crushing rollers extend to the outer side of the rack through the through grooves, the rotating shafts at one ends of the pair of primary crushing rollers are in transmission connection with primary crushing motors, the bottom ends of the pair of primary crushing rollers are provided with primary sieves and primary ramps, and one side of the inner wall of the rack is provided with a coarse material outlet; a pair of secondary crushing rollers is mounted in the rack through a rotating shaft, a secondary screen is fixedly mounted at the bottom ends of the pair of secondary crushing rollers, and a secondary ramp is fixedly mounted at the bottom end of th