Auto-test is an important technical support for the idea of "factory debugging and replaceable maintenance" for local protection. First,Introduces the main technical features of local protection. Secondly,Analyzes the demand of auto-test for local protection from three aspects: protection logic, three-network-integration function of private network and the communication of component protection ring network. Finally,Proposes two technical schemes: protection logic auto-test system and comprehensive auto-test system, and introduces the system scheme and the key technology in detail.