A domestically produced System on Chip (SOC) software online upgrade method based on Ethernet is proposed to address the complex and cumbersome process of upgrading programs through the integration of simulators, which is more inconvenient to maintain in the field. Research and implement the online upgrade process of domestic SOC chips. This method adopts dual network segments to improve the system's fault tolerance, and based on the characteristics of the domestic SOC chip, improves the power outage sequence after online upgrade to further ensure the stability of the upgrade process. This method has been applied to a certain aerospace controller and can support the simultaneous upgrade of multiple boards, proving the convenience and reliability of the upgrade method and having certain engineering application value.