Abstract: The characteristics of Brinell, Rockwell and Vickers hardness test methods were analyzed and researched. Energy method was put forward to uniformly characterize these three kinds of hardness values, and this method took the absorbing energy to form unit indentation volume (dJ·mm-3) as the measurement unit of hardness values. The results show that this method has a clear physical meaning. And under the current hardness test condition and test method, this method could organically link the three kinds of hardness test methods. According to the current Brinell, Rockwell and Vickers hardness test methods, the corresponding hardness values characterized by energy method could be obtained.