The invention discloses a dustproof bolt with a gap compensating function. The dustproof bolt comprises a pin base arranged on a door/window frame, a movable pin slidingly arranged in a door/window leaf and suitable for inserting in the pin base, a dustproof piece arranged in the pin base, and a spring for applying partial pressure to the dustproof piece in an opening direction of the pin base. The dustproof bolt further comprises a gap compensating piece arranged in an opening of the pin base, positioned in a direction of opening and closing the door/window leaf, performing a reciprocating motion in a direction of the movable pin inserted in the pin base and applying partial pressure to the movable pin.