The utility model discloses an automatic collating unit's of reagent pipe clamping mechanism, including the stroke along transfer passage's direction?of?delivery reciprocating motion's cylinder D, fix on cylinder D and along with cylinder D reciprocating motion's support, be fixed with a plurality of parallel clamping device of group on the support, every clamping device of group includes two symmetrical clamp splice subassemblies, and every clamp splice subassembly that is listed as includes a plurality of clamp splice units, the head of clamp splice subassembly, two clamp splice units on the tail and the guiding axle support that corresponds are fixed, and the guiding axle support sets up on cylinder E, and the clamp splice subassembly of two symmetries can realize along with cylinder E that the looks butt clamp tightly or relatively unclamps, cylinder E passes through cylinder F to be realized along guiding axle axial displacement. The utility model discloses the mechanical automation of reagent tube array can be realized, work efficiency has been improved. The utility model also discloses an automatic collating unit of reagent pipe.