The invention discloses an intelligent N-1 scanning method and a system for a backup automatic switch. The method comprises the following steps: establishing a mapping relationship between failure equipment and an acted backup automatic switch; when a failure is detected, determining a backup automatic switch having actions caused by the failure equipment according to the failure equipment and the mapping relationship; adopting corresponding load transfer method to transfer the loading of the working generator according to the property of the backup automatic switch having the actions caused by the failure equipment; performing current correction on the network after load transfer according to the mapping relationship. The N-1 scanning method avoids a great amount of topology calculation in a conventional method, and a great amount of calculation time is saved, so that fault processing time is greatly shortened, and the failure processing efficiency is greatly increased.