Automatic clamping test tube rack

The utility model belongs to the technical field of medical instruments, and particularly relates to an automatic clamping test tube rack. According to the technical scheme, the fixing openings are formed in the test tube rack, the test tube rack is used for fixing test tubes, when the test tubes are placed on the test tube rack, the upper portions of the test tubes can be limited and clamped through the fixing openings, and the placing stability of the test tubes is guaranteed. A guide groove is formed in the lower portion of the test tube rack and coaxially aligned with the fixing opening, tube wall clamping mechanisms are arranged on the two sides of the guide groove, each tube wall clamping mechanism is composed of a fixing piece and a plurality of elastic pieces, and when a test tube is inserted into the guide groove, the elastic pieces on the two sides of the test tube abut against the side wall of the test tube, opposite clamping force is applied to the two sides of the tube wall of the test tube, and