Abstract: Non-standard measurement of Charpy V-notch impact specimens of metallic material led to test value discrepancy seriously, and the precision of proportion graphics and the corret drawing were important means to guarantee the size and shape of impact specimens fully meet with the requirement of GB/T229-2007. So the measurement accuracy of Chapy V-notch impact specimens should be strictly controlled, the standards for inspecting notch quality with gap projector and drawing of standard figure of processing precision should be unified.