Underground override trip prevention protection method and system

The invention discloses an underground override trip prevention protection method and system. Fiber longitudinal differential protection is configured on two sides of a line between stations to serve as main protection, GOOSE network-based override trip prevention protection is configured in the stations to serve as main protection, and overcurrent protection with a delay constant value capable of being updated and optimized online is set to serve as backup protection. When a fault occurs, the fault is preferentially isolated by the main protection, and when the main protection fails or the switch refuses to operate, the fault point is quickly isolated by the updated and optimized delay constant value of the backup protection and the tripping off of the upper-level switch adjacent to the fault point, so that the selectivity and rapidity of underground relay protection are considered, and the operation reliability of an underground power supply system is improved. 本发明公开了一种井下防越级跳闸保护方法和系统，通过站所间线路两侧配置光纤纵差保护作为主保护，