The invention provides a cluster system self-construction method, a cluster self-construction device and a cluster system. When a service node determines a fault of a first management node, mutual communication is started through the service node. Each service node defines a plurality of candidate nodes from a plurality of service nodes and defines a second management node from the plurality of candidate nodes. The second management node replaces the first management node. Other candidate nodes except for the second management node in the plurality of candidate nodes perform the original sub-task of the second management node, thereby selecting the new management node in a relatively high speed when a fault of the first management node occurs. Operation suspension of the cluster system is not required, and furthermore a standby management node is not required. Reliability of the cluster is improved and high-efficiency utilization of system resources is realized, so that the cluster system can operate safely and stably.