MANET is utilized in many fields because of its advantage in quickly establishing networks. The network will perform well if mobile nodes trust each other and act cooperatively. However, dynamic topology characteristics and frequent connection failures by the movement of nodes make routing difficult and cause vulnerability to be easily exposed. Therefore, the routing provided in the MANET should have security features that can reduce the damage to various attacks. For this, in this paper, it is proposed for a trust evaluation method of nodes using cluster structure and a secure data transmission technique through key exchange without CA. The proposed technique adopted a hierarchical structure to enhance the efficiency of the reliability evaluation of nodes. The reliability measurement reflects the quality of packets as well as the number of packets and the measured reliability is maintained by the trust management node. The integrity of the data transmission is improved through key exchange without CA between the nodes. In order to increase the efficiency of routing, anomaly nodes are detected by DSN checking of nodes that generate excessive traffic on the path when data is transmitted. The proposed technique in this paper can maintain stably the network performance even in the presence of malicious nodes because it ensures reliability evaluation for nodes and the path setting between nodes and secure data transmission. The superior performance of the proposed trust-based model security routing technique was confirmed through comparative experiments for packet delivery ratio, end-to-end delay time, the number of control packets, network throughput, and average path length.