Abstract: Based on the classical three-wave method theory of the SHPB/SHTB device, a correction method for the dynamic tensile deformation measurement is proposed. The method can effectively avoid the signal interference caused by the threaded connection and transition part between the incident (transmitted) bar and the specimen. Dynamic tensile and compressive experiments of LY12 Aluminum alloy were carried out with the split Hopkinson bar devices. The method is used to correct the dynamic tensile test results for LY12 Aluminum alloy, and then the corrected tensile results are compared with the compressive ones. It is proved that this method is reasonable, feasible and practical. And the optimal size of tensile specimen is derived.