Abstract: A firmware upgrade technology for the monitoring station through the Ethernet is proposed, the technology is based on Bootloader and using Flash ROM as the carrier to implement remote firmware update. This paper expounds the principle of the technology, introduces the design of the overall scheme, the method of implementation and the specific problems needing attention. The technology ensures the accuracy of the data through the verification mechanism. On the other hand, after the interruption of the upgrade process, the program can go back to the running state of the old version of the program. The technology is stable and reliable, and avoids the complexity of traditional firmware upgrading methods and improves efficiency.