Abstract: To carry the corresponding quantitative information of the system, weighted automata are used as the models for studying the co-detectability of weighted discrete event systems. First, the notions of strong and weak co-detectability of decentralized weighted discrete event systems are formalized. Then, the algorithms based on each sub-station site observer for constructing a co-observer are proposed, and necessary and sufficient conditions for strong and weak co-detectability of decentralized weighted discrete event systems are obtained. Finally, an application example for a wireless sensor network system is provided.