Different power grid operation mode corresponds with different short-circuit capacity distribution, while different distribution of short-circuit (current) capacity is contradictory to power grid operation performance and equipment tolerance influence consequence. This paper establishes functional relationship between short circuit (current) capacity of power grid and effective switch set and feasible power grid operation mode on this basis, deploys analysis on relationship between short circuit (current) capacity of power grid and feasible power grid operation mode on the basis that an equivalent topology analysis model is built, in order to take equipment tolerance into consideration in a compromised way during making of decisions concerning with power grid operation mode and extend power grid operation scheduling.