As the core secondary equipment of the second and third line of defense to ensure the safe and stable operation of the power grid, the safety and stability control device is not high in the degree of localization of key components. Thus the transformation of localization is urgently needed. There are problems of difficulty in selecting the main control chip and the poor real-time and stability of the processor faced by the autonomy of the safety and stability control device. Thus, starting from the research of chip localization standards, a system framework for a safety and stability control device based on the Loongson processor is proposed. It mainly includes the overall platform architecture design, core function module design, real-time data interaction, compatibility design, and stability control application design based on the platform, etc. The design principle for the device platform of the autonomous and controllable stability control system is described from the aspects of hardware and software. The device designed based on the platform scheme has been put into trial operation in several substations, and in is good condition. At the same time, it has good compatibility and makes effective replacement with the devices in operation. This work is supported by the National Key Research & Development Program of China (No. 2021YFB2401000).