The present disclosure discloses an arbitration processing solution when brain split occurs in cluster. The solution includes: receiving, by a quorum storage apparatus within a first refresh packet detection period, first master quorum node preemption requests sent by at least two quorum nodes in the cluster; sending, by the quorum storage apparatus, a first master quorum node preemption success response message to the initial master quorum node indicating that the initial master quorum node succeeds in master quorum node preemption when the first master quorum node preemption requests received within the first refresh packet detection period comprise the master quorum node preemption request sent by the initial master quorum node.