Cognitive radio sensor network (CRSN) is an intelligent and reasonable combination of cognitive radio and wireless sensor networks. Clustering is an effective method to manage the network topology of CRSN. In order to solve the optimal cluster head selection problem in clustering which is proved to be NP-hard, inspired by ions motion optimization (IMO) algorithm, a novel centralized clustering routing protocol, i.e., IMO-based clustering routing protocol (IMOCRP) which can adapt to the dynamic characteristics of CRSN is presented in this paper. Optimal number of clusters and identity of cluster heads are automatically determined by combining the excellent characteristics of IMO algorithm and the rich resource, comprehensive information at the sink together. Thanks to its centralized structure, IMOCRP proposed in this paper avoids excessive overhead in cluster head selection and cluster formation, which in turn helps conserve energy. Available channel list at each living node is taken into consideration to perform reasonable channel allocation for clusters, and the probability of collisions with primary users can be reduced, which promotes more successful information delivery. Simulation results have shown that IMOCRP can balance network lifetime and effective information collection capability, and it is superior to other competing protocols. INDEX TERMS Cognitive radio sensor network, clustering algorithms, ions motion optimization, computational complexity JIHONG WANG received the B.S. degree in communication engineering from Jilin University, Changchun, Jilin in 2011 and the PhD. degree in communication and information systems from School of Communication Engineering, Jilin University in 2016. She is currently an associate professor and master supervisor in Northeast Electric Power University. Her research interests include cognitive radio sensor networks, routing and resource allocation in wireless networks, energy harvesting and so on SHUO LI was born in Changchun, Jilin, China, in 1995. He obtained a bachelor's degree in communication engineering from Northeast Electric Power University, China, in 2018. In the same year, he studied for a master's degree at Northeast Electric Power University, China, and his research direction is clustering and routing in cognitive radio sensor network. YIYANG GE was born in Changchun, Jilin, China, in 1996. She received B.S. degrees in electronic information science and technology from Northeast Electric Power University, China, in 2019. Her research interests include cluster routing protocol design and resource allocation in cognitive radio wireless sensor networks with energy harvesting.