The accounting standards for business enterprises issued in 2006 include goodwill as an asset in the balance sheet,and its amount is the difference between the fair value of net assets and the actual payment at the time of merger and acquisition.Whether the goodwill recognized as assets after M&A can bring excess profits to the enterprise,and whether the management’s cognition can have an impact,are all worthy of study.Based on the financial data of A-share listed companies in Shenzhen stock market from 2015 to 2018,this paper makes an empiric...