Auxiliary door closing device for straight elevator

The utility model belongs to elevator door opening and closing devices, and particularly relates to a straight elevator auxiliary door closing device which is characterized in that a rotating shaft is mounted in the middle of a positioning block, when the rotating shaft rotates, a gear in the rotating shaft is driven to rotate together, and the gear is located on the inner sides of two driving sliding rails; the gear moves in parallel on the inner side of the driving sliding rail to drive the positioning block to move together, the driving sliding rail is fixed through the fixing block and the buffer plate, and meanwhile the impact force generated when the positioning block makes contact with the fixing block can be reduced through the buffer plate; a pulley installed above a positioning block and above a fixing plate through a bolt is matched with a sliding groove in the top of the pulley and a driven sliding rail at the bottom of the pulley, in the using process, when the positioning block horizontally move