Zr and Ca co-doped brium titanate (BCTZ) based ceramics have attracted much attention due to their excellent dielectric and piezoelectric properties, which are potential candidates for lead-free piezoelectric materials. However, the piezoelectric property of BCTZ-based ceramics are still lower than that of commercial lead-based ceramics. Therefore, Sn elements are doped in (Ba_0.85Ca_0.15)(Ti_0.9Zr_0.1-xSn_x)O₃ (x = 0.02-0.07) ceramics to improve their piezoelectric property in this work. First, all ceramics exhibit a pure perovskite structure without any secondary phase. Furthermore, orthorhombic and tetragonal phases coexist at room temperature for all counterparts. Second, all ceramics display a dense microstructure. And the grain size gradually increases with Sn content increasing. The crystal structure of x=0.04 ceramic locates in morphotropic phase boundary. Meanwhile, the x=0.04 ceramic exhibits the most dense microstructure. Hence, x=0.04 ceramic has the best piezoelectric property with d₃₃ = 590 pC•N ^-1, k_p = 52.2%, tanδ = 0.016, ε ^T₃₃= 5372, d ^*₃₃= 734 pm•V ^-1, and IR = 57.8 GΩ•cm. This work demonstrates that the Sn-doped BCZT based lead-free piezoelectric ceramics could be applied in transducers, electromechanical sensors and actuators.