This paper proposes a system EE (energy efficiency) optimization algorithm based on OPS (On‐off Power Splitting) strategy for SWIPT (Simultaneous Wireless Information and Power Transfer) two‐way relay assisted CR‐NOMA (Cognitive Radio Non‐Orthogonal Multiple Access) network. The system capacity expression of the secondary users with the OPS strategy is derived. Under the constraints of harvested energy and quality of service (QoS) of the users, the optimization problem with the goal of maximizing energy efficiency is constructed. In this paper, the NP‐Hard problem is transformed into three subproblems about relay power, NOMA coefficient, and segmentation coefficient, which are solved by golden section algorithm, monotonicity decision function, and genetic algorithm. The simulation results show that compared with the PS (Power Splitting) and TS (Time Switching) strategies, the OPS strategy can significantly improve the transmission energy efficiency of the system.