The invention discloses an operation method of an intelligent substation of an alternating-direct current hybrid power grid. The operation method comprises following steps of S1, establishing an expansion model of an operation device of the intelligent substation; S2, making a rule based on a comprehensive combination unit, an alternating-direct current stability control unit, a switch intelligent unit and a voltage combination unit of an expert system; and S3, according to the rule of the comprehensive combination unit, the alternating-direct current stability control unit, the switch intelligent unit and the voltage combination unit, executing a corresponding expert system strategy. According to the invention, based on related concepts of a semantic net, logics between different concepts of an expert system knowledge library are quite clear and uniform; and through the established rule and strategy, an objective of improving expandability and practicability of the expert system knowledge library is achieved.