A new kind of piezoelectric actuation structure named double amplified multilayer actuator is proposed. Double amplified multilayer actuator combines both dimentional and flextensional amplification concepts. As a result the displacement of the actuator can be more than one hundred times larger than the displacement of multilayer actuator and can be used in in-pipe locomation robot such as an endoscope actuator. This paper studied the dependence of displacement on actuator parameters theoretically and experimentally.