Abstract: In the face of the complexity and high cost of software update for embedded devices and NB-IoT has less uplink and downlink transmission data, a remote software update system was designed. And optimize the hardware and software to save the network overhead required to update and shorten the update time. The system makes a reasonable division of the terminal nodes Flash, design the bootloader area and the drive curing area, and reduces the code update area at the hardware level. And use the text comparison algorithm Needleman/Wunsch in the server software to avoid duplicate code data transmission at the software level. Finally, the remote update system is tested. The test results show that the system has less update code, shorter update time, and better success rate.