This paper investigates the problem of security couple-group consensus for second-order multi-agent systems under DoS attacks. Different from the related studies, more complex non-periodic multi-channel independent DoS attacks are considered in our work. Comprehensively considering the cooperative and competitive interactions among the agents, a novel protocol with a state estimator for realizing security couple-group consensus is proposed. On basis of the protocol, the constraint condition for the duration of DoS attacks is given. Meanwhile, the decay rates under different attack modes are obtained by designing appropriate Lyapunov functions and solving the algebraic Riccati equations. To solve the problem that the decay rate is difficult to match with the channel, the equivalent decay rate corresponding to each channel is introduced. In addition, the stability criterion of the system is also given. Finally, several numerical simulations are designed to illustrate the correctness and effectiveness of the results.