With the continuous advancement of industrialization, high-precision actuators are increasingly being applied in fields requiring high accuracy, such as aerospace, smart vehicles, and robotics. However, the current mainstream actuator materials on the market are lead-containing ceramics primarily composed of lead zirconate titanate (PZT). During the manufacturing process, these ceramics produce lead and lead oxide, both of which are highly harmful to the environment and human health. Therefore, the development of lead-free ceramics capable of serving as high-precision actuator materials is urgently needed. As the most widely studied lead-free system, perovskites have rightfully become the most extensively investigated lead-free material family. Among them, barium titanate (BaTiO₃)-based lead-free ceramics, one of the most promising systems, have attracted widespread research due to their excellent stability and favorable electro-strain properties. However, although phase boundary engineering, the construction of polar nanoregions (PNRs), and defect engineering have partially improved the strain hysteresis of ceramic materials, these advances still fall short of meeting the demands of high-precision actuators.