Abstract: High power cylindrical transducer is widely used in cleaning, contaminant separation and extraction.In order to exert the maximal mechanic capability of PZT for the purpose of high power radiation, a new type cylindrical transducer preloaded by heating the metal casing A new type cylindrical transducer preloaded by heating the metal casing is introduced in this article.Preload stress is analyzed by the finite element simulation software ANSYS.The re-lationship between the thermal stress and the attribute of the metal casing such as material, thickness and heating tem-perature is obtained through analysis.According to the optimized results, transducers have been made.Experiments show that the transducers have good performance.