The invention relates to a station domain expanded differential protection method and system for coping with information loss. The method includes the steps that when a current transformer spaced to any station domain differential protection circuit is abnormal, a current transformer on the opposite side of the abnormal current transformer circuit is used for participating in station domain differential protection calculation; if a fault appears in a station domain differential protection range, a trip command is sent to a circuit breaker on the same side with the abnormal current transformer after a first delay; if the circuit breaker on the same side with the abnormal current transformer does not successfully trip off, trip commands are sent to all spherical circuit breakers of the abnormal current transformer after a second delay. The circuit breaker on the same side of the abnormal current transformer trips after the first delay, if it is detected that the circuit breaker on the same side successfully trips off, the peripheral circuit breakers of the abnormal current transformers do not need to trip off, and the peripheral circuit breakers of the abnormal current transformers only trip off when the circuit breaker on the same side cannot successfully trip off, and the phenomenon of fault expansion is effectively inhibited.