It is of great practical significance to improve the sensitivity and enhance the stability of lead zirconate titanate (PZT) piezoelectric ceramics under hydrostatic pressure condition. In this work, the xPb(Sb_1/2Nb_1/2)O₃-(1-x)Pb(Zr_0.52Ti_0.48) (PSN-PZT, x=0.018, 0.020, 0.022, 0.025, 0.030) piezoelectric ceramics were prepared with conventional solid-state method. The influence of PSN on the phase, microscopic morphology, curie temperature, dielectric property, ferroelectric property, and piezoelectric properties of ceramics has investigated. The sensitivity of PSN-PZT and traditional high sensitivity piezoelectric ceramics was measured comparatively within the hydrostatic pressure of 5 ～ 30 MPa. The results show that the incorporation of PSN can improve the sensitivity and enhance the hydrostatic figure of merit (HFOM) of PZT piezoelectric ceramics significantly. When x=0.020, the PSN-PZT ceramics have the best electric properties, planar electromechanical coupling factor k_p=0.641, longitudinal piezoelectric strain constant d₃₃=325 pC/N, transverse piezoelectric voltage constant g₃₁=16.642 mV·m·N^-1, isostatic piezoelectric voltage constant g_h (5 MPa)=9.91 mV·m^-1·Pa^-1, HFOM (5 MPa)=679×10^-15 Pa^-1.