Aim at the shortcomings of existing measures of scholar evaluation,we present a new method to scholars impact evaluation from social network perspective based on the centrality index and co-author network.Two groups of core authors established from this method and traditional published papers method are compared.Applying the three centrality ranks could discover different type of authors.The typical authors and their network structures are analyzed.Finally the deficiencies and improvements of the method are proposed.Evaluating scholars by peer review,papers productivity,citation analysis,co-network analysis,and other various methods together will get more comprehensive and objective result.