The surface heat transfer coefficient, as a key control parameter of quenching, plays an important role in the numerical simulation of quenching process and has a great influence upon the microstructure and residual stress in workpiece. In this paper, the surface heat transfer coefficient during quenching is analysed and defined and some of the evaluation methods of surface heat transfer coefficient proposed by researchers are studied based on literature, so as to point out some of the research achievements and trends to the readers.