In this paper,Pb(Sn0.5Nb0.5)O3-Pb(Ni1/3Nb2/3)O3-Pb［ZrxTi(1-x)］O3（PSN-PNN-PZT,x=0.42, 0.43,0.44,0.45）piezoelectric ceramics were prepared by the conventional solid phase reaction method. The effects of different content of x on the phase structure, microstructure morphology, and the electrical properties of PSN-PNN-PZT piezoelectric ceramics are investigated. The results show that when x=0.43, the sample is single perovskite structure and possesses a quasi phase boundary, the grain is full, the interface of crystal grains is clear and the particle size is uniform. The ceramic exhibits the optimum properties with the piezoelectric constant of d33=625 pC/N,dielectric constant of εr=3 005，dielectric constant of tan δ=1.75%，capacitance of Cp=1 280 nF.