Abstract: Considering the security resource allocation problem in the two-way relay networks exiting an eavesdropper, to improve the security of the relay, a security secrecy ratio scheme under the constraint of subchannel allocation and power is studied in this paper. Compared to the traditional secrecy capacity scheme, the security secrecy ratio scheme pays more attention to reflecting the users own security extent. Based on the proposed scheme, security Quality of Service (QoS) requirement for different users and the network fairness are further considered. Besides, power allocation, subchannel allocation and subchannel pairing are joint considered. Then, the optimal solution is obtained through Constraint Particle Swarm Optimization (CPSO) algorithm, Binary CPSO (B_CPSO) algorithm and Classic Hungarian Algorithm (CHA), respectively. Finally, the network resources are allocated in an optimal manner and the secrecy ratio for legitimate users is improved. Simulations results show the effectiveness of the proposed algorithm.