Disclosed are a sensing network system, and nodes and a data processing method thereof. The sensing network system comprises a plurality of nodes that are connected with each other. Each node has a sensing device and a storage device. The storage device of each node is divided into a first storage area and a second storage area. The first storage area stores data sensed by the sensing device of the node. The second storage area stores at least a part of the data sensed by the sensing device of at least one of other nodes. The node transmits at least a part of the data sensed by its sensing device to at least one of other nodes, in order to store at least a part of the data sensed by its sensing device in the second storage area in the storage device of at least one of other nodes.