Tractor gear-locking device

The utility model relates to an accessory of agricultural machinery, in particular to a tractor gear-locking device. The tractor gear-locking device comprises a gearbox shell and a shift fork shaft installed in the gearbox shell. A positioning steel ball is arranged in the inner wall of the gearbox shell; a shift fork shaft groove matched with the positioning steel ball is formed in the outer surface of the shift fork shaft; the positioning steel ball is installed in a shell penetrating hole penetrating through the gearbox shell; a spring and an ejection rod are further installed in the shell penetrating hole; a shaft seat is arranged in the position, corresponding to the shell penetrating hole, of the outer wall of the gearbox shell; an axle hole perpendicular to the shell penetrating hole and an ejection rod hole are formed in the shaft seat, wherein the ejection hole and the shell penetrating hole are coaxial; a gear-locking shaft is inserted in the axle hole; a gear-locking groove is formed in the positio