Expansion type drawknot screw

The utility model discloses an expanding type tie screw rod applicable for temporary or permanent bonding of buildings, which is used for substituting embedded steel dowels of posts and beam plates, bonding in the formwork erection of posts, etc. The expanding type tie screw rod pertains to the constructional components connected with a building structure which consists of an expanding bolt and a tie bar with screw threads, wherein, the expanding bolt is matched and connected with the tie bar in a screw way. The expanding type tie screw rod has simple structure, convenient installation and flexible use and also has the functions of bonding, load bearing, etc.