Embodiments of this application relate to an intra-cluster node troubleshooting method and device. The method includes: obtaining fault detection topology information of a cluster, where the fault detection topology information includes a fault detection relationship between all nodes in the cluster; obtaining a fault indication message, where the fault indication message is used to indicate unreachability from a detection node to a detected node; determining a sub-cluster of the cluster based on the fault detection topology information and the fault indication message, where nodes that belong to different sub-clusters are unreachable to each other; and determining a working cluster based on the sub-cluster of the cluster. According to the embodiments of this application, available nodes in the cluster can be retained to a maximum extent at relatively low costs. In this way, a quantity of available nodes in the cluster is increased, high availability is ensured.