In view of the status quo of power secondary system security protection lacking in central control and means of statistical analysis，a design and implementation scheme for an inner net security monitoring platform in power secondary systems is proposed.The security monitoring platform consists of two major parts，wide area network（WAN）security monitoring and local area network（LAN）security monitoring.The former carries out real-time monitoring of the operation status of secondary system security devices by log collection of these devices，gives real-time alarm and analysis of security incidents.The latter performs real-time monitoring of the security operation status of important dispatching support system equipments by log collection.Operation practice in Jiangxi power grid shows that the security monitoring platform can help operators learn about the operation conditions of secondary system security devices and remove hidden security hazards in time，which is of great significance to ensuring safe and stable operation of the power grid.