In order to solve the problems of low packet processing rate and poor protection effect of the traditional power monitoring network security protection system, a power monitoring network security protection system based on the Commercial Cryptography is proposed in this study. According to the basic functional requirements of the system, the hardware part of the system is designed. In the software backup of the system, the identity authentication module and data encryption module are designed by using the commercial encryption algorithm, which ensures the security of data transmission within the network. In the system test, the packet processing rate of the system is tested. The test results show that the designed system can handle more than 95% of the packets with different flow rates, and has a high packet processing rate and good protection effect. Therefore, it can be proved that the designed system can be applied to network security, which is of great significance to the development of network information security