Lead zirconate titanium solid-solution (PZT) thin films with various thickness are synthesized on titanium substrates by repeated hydrothermal treatments.Young modulus,electric-field- induced displacement and the density of the PZT film are measured respectively.Bimorph- type bending actuators are fabricated using these films.The model,which is used to analyze the driving ability of bimorph-type bending actuators by hydrothermal method,is set up.It can be seen that the driving ability of bimorph-type bending actuators can be greatly improved by optimizing the thickness of PZT thin film and substrate from the theoretical analysis results.The measured values are expected to agree with the theoretical values calculated by the above model.