A method of checking connection states of source nodes in a cluster is carried out by host computer, collecting information of a source node of each monitored computer, and generating a checking list. Each source corresponds to a plurality of network interface, and each network interface corresponds to a plurality of target nodes. At least one source node is selected as a to-be-checked source node. Each to-be-checked source node confirms the corresponding target nodes based on an instruction to detect network. Connection states between each to-be-checked source node and the target nodes are detected. A reason for detection failure is confirmed based on the result of detection and the checking list. An electronic device and a computer readable storage medium applying the method are also disclosed.