The current information exchange interface and human-computer interaction interface of secondary equipment operation and maintenance in substation are not unified,which seriously restricts the efficient operation and maintenance of substation. In view of this situation,the research on the efficient operation and maintenance technology of secondary equipment in substation based on power system general service protocol (GSP) is carried out. Firstly,the architecture of integrated operation and maintenance of secondary equipment in substation is designed,and the information modeling method of integrated operation and maintenance of secondary equipment in substation based on substation operation and maintenance configuration language (SOMCL) is proposed. Then,the service interface and information interaction mechanism of integrated operation and maintenance of secondary equipment in substation are designed based on object-oriented technology (OOT),which achieves the goal of plug and play information interaction between operation and maintenance tools and the object to be transported. Finally,the integrated operation and maintenance tool of secondary equipment in substation is developed to realize the standardization and visualization of operation and maintenance of intelligent secondary equipment in substation,and achieves the goal of integrated and efficient operation and maintenance of secondary equipment in substation. The proposed method has been piloted in several new smart substations,which verifies the feasibility of the integrated operation and maintenance technology of secondary equipment in substation.