On the basis of a new type of functionally gradient (FG) piezoelectric actuator proposed by the authors in their former study,the new actuator is designed, fabricated, modeled and experimentally studied. The material compositions are selected from Pb(Ni1/3Nb2/3)O3-PbZrO3-PbTiO3 family and they are used as the four layers in the new FG piezoelectric actuator.The piezoelectric constants and dielectric constants of the materials are gradated oppositely in the thickness direction, because this special structure of the FG piezoelectric actuator has an advantage over the traditional actuators in internal stress distribution. To optimize the structure of the FG piezoelectric actuator, an electromechanic model is derived from Classical Lamination Theory (CLT) and piezoelectric equation, and the static distortion and stress distribution of the actuator with different thickness ratios are computed when the voltage or concentrated force effects on it independently.The optimum thickness ratio is 1∶1∶1∶1, which is determined by optimizing the internal stress distribution.According to the optimizing result,the FG piezoelectric actuator is fabricated successfully,also the relation between the output displacement and output force at the free end of the actuator is measured. The experimental results indicate that there is a linear relation between the output displacement and output force of the actuator, moreover, the lower vibration frequency is, the greater output displacement and output force are.