We should renew people's ideas on the basis of inheriting modern financial theory and make a great breakthrough in financial theory. The theory and method of modern financial management can not meet the needs of network financial management in the 21st century. It is mainly manifested as follows: the traditional financial management theory is based on industrial economy, which is not suitable for the requirements of knowledge economy; the traditional financial management means are backward; the strict financial system; the risk management scope of traditional financial management is narrow; the financial evaluation system is limited to the financial indicators measured by currency, ignoring the evaluation of human resources and knowledge assets. In addition, there are many unpredictable risk factors, which make the network financial risk more complex and difficult to identify. The traditional risk theory is still difficult to consider new uncertain factors and guide the practice of network financial management correctly. Therefore, without the corresponding theoretical guidance, the implementation of network financial is difficult.