A piston rod dustproof structure comprises a piston rod, a connecting lifting lug fixed to the axial end of the piston rod and a dustproof cover cap which comprises a round substrate perpendicular to the piston rod, the side, away from the connecting lifting lug, of the peripheral edge of the substrate vertically extends to form a cylindrical extending part, the middle of the substrate swells upwards to form a swelling portion, a through hole is formed in the center of the swelling portion, the side, facing the connecting lifting lug, of the edge of the wall of the through hole vertically extends to form a cylindrical connecting portion, and the inner wall of the connecting portion and the piston rod are welded. According to the piston rod dustproof structure, the cylindrical connecting portion and the piston rod are welded, through the swelling portion, the structural strength of the dustproof cover cap is enhanced, and therefore the piston rod dustproof structure is higher in strength, is not prone to loosening in the use process and long in service life.