Because the precise positioning technology with micro/nanometer resolution plays an irreplaceable role in insitu testing, precision optics, ultraprecision processing and other fields, various new actuators with precise positioning functions have been attracted wide attention of both domestic and foreign scholars, especially piezoelectric inchworm actuators. They bear obvious comprehensive advantages among all actuators, such as high positioning accuracy, compact structure, large output force, stable motion, large working stroke and high motion resolution. Firstly, the principle and key components of piezoelectric inchworm actuator are introduced. Secondly, the research progress of three representative inchworm actuators (i.e., linear, rotary and integrated) are summarized, and their main structures, action principles, characteristics and applications are analyzed.The results show thatpracticality is the key issues of future research, which can be implemented from the aspects ofconfiguration design, control system,compensation algorithm and temperature control, etc.