The necessity of smart distribution grid secondary system integration is analyzed based on the physical form of smart distribution grid and the production and operation characteristics in the entire process. The common information model and interface specification of distribution network in IEC 61970 / 61968 international standard are emphatically discussed, and the unified model of the equipment of smart distribution grid is established by expansion. The technology architecture for secondary system integration of smart distribution grid is analyzed from three aspects including the integrated structure of secondary system integration based on information interactive bus, the service-oriented information interactive architecture and metadata technology. The technology architecture is proved feasible by a practical application case, which can provide a reference for promotion of smart distribution grid application systems.