Abstract: Security and stability control（SSC） system is very important to ensure the safe operation of power grid. In view of the insufficiency that the current open-loop test method cannot fully test the on-site SSC system, a remote closed-loop test method is proposed based on real-time simulation. The solutions of key techniques such as information interaction, remote communication and signal conversion in remote test system are studied. Then the platform architecture and standard interface of the remote test system are designed. A remote test platform for SSC system is developed, and the application modes of the platform are deeply analyzed. Finally, taking SSC system of AC output interface in Yunnan as a pilot application, on-site joint remote tests of two main substations are carried out. The results in the practical project further prove the effectiveness of the proposed method.