Lead magnesium niobate-lead titanate ((1-x) Pb (Mg1/3Nb2/3-xPbTiO3, PMNT) solid solution thin films were prepared on silicon substrates by Sol-Gel method. The well crystallized thin films were prepared on 700°C for 1 hour and micro-patterning of PMNT thin films were researched by wet etching. PMNT etch rate higher than 2.4μm/min could be obtained with well etch profile by using HF/HNO3/H2O. XRD analysis and ferroelectric property test showed that there were not the crystal lattice distortion and ferroelectric property change during PMNT etching. In the paper, the key technologies in the preparation and patterning of PMNT thin films were solved and had laid good technology foundation for the preparation of silicon-base ferroelectric thin film microfabricated devices.