PORM knowledge system is created by the RRM laboratory of Public Opinion Monitoring Room of People’s Daily Online. The philosophies，principles and methods used in public opinion risk management practice involve multi-disciplinary and multi-field，mainly contain management by objectives，system feedback and power drive，organizational evolution，cognitive management，function cellularization and anti-fragile and so on. During the practice of public opinion risk management，PORM knowledge system is mainly reflected by three major items of cognitive management，risk management and crisis management. This article，take A company of industry as an example，specifically described preliminary application of PORM knowledge system in the public opinion risk management practice. Based on PORM knowledge system，public opinion risk management can make the pass of risk forward and achieve whole process management. It can improve the perspectiveness and pertinence of crisis management，reduce the difficulty and cost of crisis management. It represents a new business model of public opinion service industry. However，because exploring the source of risk will easily lead to the reject reaction of the organization for the system involves complex systems management，as well as the risk information system needs a data technology support and other factors，the public opinion risk management based on the PORM system needs to be further improved in the process of practice.