To improve and ensure the efficiency and reliability of control strategy for power grid security and stability control system (SSC), an automatic programming realization method using a UML activity diagram for the SSC strategy is proposed and the corresponding basic platform is developed. First, the least dynamic behaviors elements of the SSC strategy are extracted to propose stability control strategies dynamic behavior description methods. The stability control model and an abstract syntax tree based on UML activity diagrams are thus established. After that, the storage standard and format of the SSC strategy model is regulated, the model-to-code mapping rules are formulated, and the model is automatically converted into embedded system executable code using depth first search based on the abstract syntax tree. Finally, a technical software framework which automatically generates the main body of code from the SSC strategy model and automatically completes auxiliary code is constructed, developed, and realized. The results of the programming cases for 4 large-scale power grid stability control system construction and renovation projects have proven the feasibility, efficiency and reliability of the proposed code automatic generation method and platform tools. This work is supported by the Science and Technology Project of the Headquarters of State Grid Corporation of China (No. 5100-202055019A-0-0-00).