The invention discloses a method for controlling and switching a redundancy electronic control system of an engine. Digital signals are used between active-standby circuit wafers for monitoring active-standby state in real time; active-standby control commands are generated according to monitor information; wherein, the monitor on the active-standby state is realized mainly by comparing characteristic signals passed by an opposite site; continuous new characteristic signals are used for determining whether the state of the opposite site is normal or not; the control state of a logic circuit is determined and switched according to the information of the active-standby state so as to increase accuracy and reliability of switching. The method has the advantages of flexible setting, simple, reliable, and stable structure.