Abstract: RAINBOW（Reduced And Internally Biased Oxide Wafer）actuator is a type of actuator with characteristics of ultrahigh displacement and moderate load capacity. This kind of actuator based on PZN-PZT（lead zinc niobate-lead zirconate titanate） was prepared.The preparation methods and parameters were investigated. The piezoelectric, displacement, resonant and ferroelectric properties of RAINBOW actuator were studied by experimental measurement. The results show good displacement characteristics and asymmetry of polarization and displacement under positive and negative electric field.