This paper is concerned with event-triggered mixed H∞ and passive control for linear systems via dynamic output feedback controllers. The system outputs are grouped into multiple nodes, in which different senors sample the corresponding data with a same period. A decentralized event-triggering scheme is introduced to select those necessary data packets to be transmitted so that communication resources can be significantly saved while preserving the prescribed closed-loop performance. First, to organize the decentralized data packets transmitted from the sensor nodes, a data packet packet (DPP) is used to generate new signal once its stores are updated at some time instants. Second, under the mechanism of the DPP, the closed-loop system is modeled as a linear system with an interval time-delay. Employ Lyapunov functional method to formulate a novel sufficient condition such that the closed-loop system is asymptotically stable with the mixed H∞ and passive performance. Third, an LMI-based approach is proposed to co-design both event-triggering schemes and desired dynamic output feedback controllers. A satellite control system is given to demonstrate the effectiveness of the method proposed in this paper.