Abstract: In order to understand the vibration characteristics of the ultrasonic horn for glass vibration molding at high temperature, a horn with a required frequency is designed based on longitudinal vibration theory, and a parameterized model of the horn is established with Creo2.0 software. Considering the material properties change of the horn at high temperature, the corresponding modal analysis is made, the resonance frequency of the horn is obtained by simulation analysis and the resonance frequency decreases with increasing temperature. In order to improve the frequency stability of the horn at high temperature, structural optimization design is carried out by finite element software. The horn is manufactured according to the optimized size, and the resonance frequency is tested by experiment. The experimental results indicate that the resonance frequency of the horn remains stable near the set frequency at high temperature.