Utilizing lead-free dielectric materials for mechanical energy harvesting and energy storage is an inevitable choice for environmental friendly energy storage devices. In this paper, (1-x) [(K_0.5Na_0.5)(Nb_0.9Sr_0.05Ta_0.08)O₃]-x(CaZrO₃) (KNN-CZ, x=0, 0.05, 0.07, 0.09) ceramics were prepared by solid-state reaction method, and their phase structure, microscopic morphology, dielectric and energy-storage properties were systematically studied. The results show that the KNN-CZ ceramics exhibit good relaxation and the P-E hysteresis lines are “thin”, which is due to the long-range ordered structure of KNN is destroyed by doping. Among them, 0.93KNN-0.07CZ has the best energy storage performance with effective energy storage density of 1.98 J/cm³, which is due to the higher energy storage efficiency (83.19%) and breakdown field strength (250 kV/cm) at x=0.07. The above results provide an environmentally friendly and promising material for ceramic capacitors.