The invention discloses an electric meter SOC system and an initialization method thereof. The system comprises an on-chip microcomputer system (MCU) and a flash memory, and further comprises a flash interface circuit which is connected between the MCU and the flash memory and a serial peripheral interface (SPI); and the method comprises an MCU initialization method and an SPI initialization method. In the electric meter SOC system, system interfaces of flash (flash memory) with two initialization methods can flexibly perform erasing, reading and writing, and verification operations on flash so that the MCU in the SOC system can manage and read the flash, and input and store data to be stored such as electric energy to the flash so as to avoid ordinary E2PROM; and the system interfaces canrealize IAP in the electric meter SOC system so as to facilitate software development and application.