Abstract: Piezoelectric ceramic is the main actuator of deformable mirror, which is the core device of adaptive optics system. Its performance directly affects the correction ability of deformable mirror and even adaptive optics system. Performance parameters of the tensile/compressible piezoelectric ceramics (5 mm×5 mm×38 mm) with loading voltage of ±350 V were tested, including displacement, hysteresis, capacitance, impedance and coefficient of thermal expansion, etc. The test results show the tensile capacity of three samples was more than 250 N, and 10 million fatigue tests (±150 N@5 Hz sinusoidal load) were carried out on 5# sample. The experimental results show that the displacement and capacitance of the sample reduced than 5%. Through the tensile/pressure and fatigue test, the properties and service life of the piezoelectric ceramic were examined, which provides some supporting data for the development of deformable mirrors.