This paper selects the intermediary agency cost conduction paths,and agency cost is included into the research on CFO financial executive ability and enterprise extreme performance.Financial data was used to depict agency cost and describe environmental dynamics.The data of A-share listed companies from 2012 to 2017 in Shanghai and Shenzhen Stock Exchanges was selected as samples for empirical test.The results show that there is a negative correlation between CFO financial executive ability and enterprise extreme performance.In other words,the greater CFO financial executive ability,the lower the agency cost,the less likely it is to produce enterprise extreme performance,the more able it is to restrain the occurrence of enterprise extreme performance.Agency cost plays a part of intermediary role in the impact of CFO financial executive ability on enterprise extreme performance.Further research finds that environmental dynamics negatively regulates the impact of CFO financial executive ability on agency costs and enterprise extreme performance.