Audit can understand the financial activities of enterprises and contribute to tax planning of enterprises. Of course, in addition to understanding the financial situation of enterprises, we must also have certain legal knowledge, understand what is legal and what is illegal, and draw a clear line between legal and illegal, so as to ensure the legitimacy of our economic activities and related behaviors as a whole. At the same time, we should have in-depth understanding and research on the tax law and the specific methods of government tax collection, and know some specific operating procedures and tax reduction space in tax management.