Using the Pb(Ni1/3Nb2/3)O3-Pb(Zr0.41Ti0.59)O3(PNN-PZT) as the basic system, the phase structure, microstructure and electric properties of PNN-PZT ceramic samples are analyzed by adjusting the mass of sintering aids CuO (x%) and LiBiO2 (y%) according to the mass ratio, and the effects of sintering aids on the ceramic samples are discussed. The results show that the ceramics are sintered into ceramics at 940-960 ℃, and the grain growth is more adequate. When x=0.2, y=1, the ceramic samples have optimal electric properties with piezoelectric constant d33 of 608 pC/N, electromechanical coupling coefficient kp of 0.65, dielectric loss tan δ of 2.19%, and dielectric constant εr of 3 843. A stacked piezoelectric actor with size of 7 mm×7 mm×36 mm is prepared by using the ceramic powders with the sintering aids mass ratio of x=0.2 and y=1, and its microstructure morphology and displacement characteristics are investigated. The cross-sectional microstructure of stacked piezoelectric actuator shows that the electrode layer was closely bonded to the ceramic layer and no cracks and gaps are created. The displacement test results show that with the increase of voltage, the displacement also gradually increases, and the maximum displacement is 46.280 μm at 150 V.As the displacement increases, the hysteresis decreases gradually.