The utility model discloses a quick locking fastener unit, combination fastener, drag link and door shape frame, the fastener is including round pin axle, oblique tight, the first semicircle clamp of wedge lock and second semicircle clamp, the voussoir is in when locking, and two locking working faces on the voussoir are located the common plane both sides of fastener unit respectively, and this common plane forms through the axis of two parallels, the axis of arc surface in the axis of these two parallels is in axis and the first semicircle clamp of round pin axle respectively, the combination fastener comprises two fastener units, horizontal draw -bar box draws together the fastener unit at pull rod main part and both ends, and the axis of pull rod main part is located the symmetry plane of fastener unit, door shape frame includes door shape frame main part and the four corners fastener unit that is formed by pipe welding, and four symmetry plane coincidences of four fastener units. The beneficial effects of the utility model are that, four have the same fastener structures, and its locking is reliable, when being used for support system to take tearing open, system stability is good, the potential safety hazard is little, takes to tear open efficiently, and construction cost is low.