The invention discloses a dog-bone type weakening and supporting structure testing machine damping device, and belongs to the field of damping control. The damping device comprises weakening section supports, elastic section supports, connecting steel plates and bolts. Dog-bone type weakening supports are arranged between a lower cross beam and a foundation of the structure testing machine, and the dog-bone type weakening supports are symmetrically arranged around a specimen; the dog-bone type weakening supports are formed by combining the weakening section supports and the elastic section supports through the connecting steel plates and the bolts; the dog-bone type weakening supports and the specimen are forced together until the load is downloaded; and a force sensor is arranged at the lower end of the specimen to measure the load on the specimen. According to the damping device, the dog-bone type weakening supports are arranged in the test process of the large structure testing machine, the vibration problem of the testing machine and the surrounding environment caused by the brittle failure of the specimen can be solved, and the advantages of artificially controlled yield and economical benefit are achieved.