The invention discloses an improved soybean crushing device. The improved soybean crushing device comprises a support frame, a first connecting rod, a first crushing box, a second crushing box, a feed pipe, a first rotating shaft, a first motor, a rotating wheel, a crushing plate, a crushing shaft and a second motor; the head end of the first connecting rod is eccentrically mounted on the rotating wheel, and the tail end of the first connecting rod is hinged with a push rod; the tail end of the push rod is connected with the crushing plate; a guide sleeve is mounted on the inner wall of the first crushing box; the first crushing box is transversely inserted with a pullable plate below the feed pipe; a mounting groove for inserting in the head end of the plate is formed in the inner wall of the first crushing box; a discharge pipe is mounted at the bottom of the right side of the second crushing box; multiple cutters are mounted on the outer peripheral wall of the crushing shaft; a spiral blade is additionally mounted on the outer peripheral wall of the crushing shaft; the crushing shaft takes the shape of a circular table; and the circular cross section diameter of the right end is larger than the circular cross section diameter of the left end. The improved soybean crushing device can fully crush soybeans to prominently improve the soybean crushing effect.