Based on IR46 standard promoted by International Organization for Legal Metrology, the biggest difference between smart meters and existing smart meters is the improvement of the reliability of the metering part. While the non-metering part is required to have the program upgrade function, the stable work of the metering part should not be affected. According to the interpretation of the IR46 standard, China State Grid Corporation put forward the idea of "Dual- Core" design, and we will discuss the realization of the "dual core" meter design.