Abstract: If the local main protection or backup protection fails to operate in time, it may cause the remote backup protection to operate, expand the scope of the accident, cause a large-scale transfer of power flow, and eventually lead to a blackout. The traditional sequential quick action can realize the quick action of section II distance protection, but it is not applicable to the high-voltage line with sequential tripping. The dynamic process including tripping action after fault occurs is discussed. For the fault in the terminal area, after the circuit breaker on the opposite side trips, the amplitude of fault phase current increases and the amplitude of zero sequence current decreases; For the fault of the next line, after the circuit breaker of the next line trips, the fault phase current will drop to the load current or close to zero, and the amplitude of zero sequence current will drop. The criterion of asymmetric successive quick motion can be constructed. Theoretical analysis and simulation experiments verify the effectiveness of the new principle.