Abstract: A mesh network system includes a plurality of network nodes. The network nodes are communicatively connected to each other to form a mesh structure. The network nodes include a first node and at least one second node. The first node is configured to obtain an update file in response to an update trigger command and send an update notification to the at least one second node respectively. Each of the at least one second node is configured to obtain the update file from the first node in response to the update notification. The first node and the at least one second node perform an update procedure simultaneously according to the update file.