Abstract: This study takes a 110 kV substation as an example for unmanned transformation design. By establishing an intelligent monitoring and early warning system architecture, implementing online multi-parameter acquisition of key equipment, and endowing it with remote control emergency response capabilities, a complete closed-loop unmanned operation and maintenance system from status perception, fault diagnosis, strategy decision-making to instruction execution can be achieved. Through three months of parallel testing under manual monitoring conditions in the case substation, it was shown that the system monitoring availability reached 99.8%, the fault diagnosis accuracy was 98%, the remote control execution success rate was 99.5%, and the accuracy of various sensor data was controlled within 1%. This proves that unmanned transformation significantly reduces operation and maintenance costs and is an important foundation for the transformation of substations to intelligence.