The invention discloses a fast upgrade method of an embedded system. The method comprises the steps of transmitting a configuration file which is used for upgrading to embedded equipment which needs to be upgraded, and replacing original configuration files in the third partition area; restarting the system; deciding a starting mode by judging whether a system starting mark is arranged in the second partition area or not after the system is powered on; reading a factory original configuration file in the first partition area to start the system if the system starting mark is arranged in the second partition area, and copying the factory original configuration file in the first partition area to the third partition area; or loading a configuration file from the third partition area to start the system if the system starting mark is not arranged in the second partition area; then setting a system starting mark in the second partition area; then judging whether the system is successfully started or not, restarting the system if the system is not successfully started, or clearing the starting mark in the second partition area and judging whether upgrading is conducted successfully or not, and re-conducting upgrading if upgrading is not conducted successfully. According to the fast upgrade method of the embedded system, system upgrade can be quickly conducted; meanwhile, the system can be quickly restored after upgrading is not conducted successfully so that the system can be normally started.