Abstract: To meet the requirements of co-phase diffraction limit imaging, a high resolution tip/tilt mirror(TM) for multi-mirror ground-based telescope is proposed and designed. Three dumbbell-shaped flexible hinges and rhombus attenuated displacement structures (RADSs) were used in the TM system as the moving transmission devices, and three piezoelectric stack actuators (PSAs) were applied as driving components. The structure parameters of the flexible hinges and RADSs were optimized by theoretical, experimental and simulative methods. The experimental results show that the TM has an extreme high angular resolution of 0.017″, and the mechanical excursion angle is larger than 0.24′ with a natural frequency of 136.97 Hz, which accord well with the results of the theoretical estimation and finite element analyzing (FEA) simulation. The high angular resolution property indicates the multi-mirror telescope can achieve the imaging in diffraction limit.