The invention discloses a maintenance isolation latching system. The system comprises authority cards for setting maintenance authority, a host computer for receiving a maintenance task and generating a latching operation instruction according to the maintenance task, an isolation key for receiving the latching operation instruction and unlocking a corresponding isolation lock according to the latching operation instruction, and isolation locks for verifying whether the latching operation instruction received by the isolation key matches with preset unlocking information and executing unlocking if the instruction matches with the preset unlocking information, and the host computer is further used for producing an unlocking instruction after the isolated device is maintained, producing an unlocking instruction and transmitting the unlocking instruction to the isolation key to unlock the isolation lock when it is verified that maintenance permissions of all the authority cards are valid. The system can facilitate the equipment isolation operation. The invention also provides a maintenance isolation latching method.