Abstract: The wettability between the metal phase and the ceramic phase plays an important role in the properties of the ceramic cutting tools. To improve the solid−liquid interface structure and enhance the comprehensive properties of the ceramic materials, the influence of the energy generated by ultrasonic during sintering on the wetting angle between the metal phase and the ceramic phase was studied. According to the theory of powder liquid phase sintering, the wetting model of the solid−liquid double spherical crown was established. Based on the wetting model and the minimal energy principle, the relationship among the wetting angle, surface energy, ultrasonic energy, and geometric parameters was established. The result shows that, the surface energy between the solid and liquid phases and between the liquid and gas phases increases by the ultrasonic wave, which is conducive to the progress of the liquid phase sintering and reduces the wetting angle; the part of acoustic energy is converted into the heat energy, which affects the wetting angle; when the ultrasonic frequency and amplitude increase, it is also beneficial to reduce the wetting angle and improve the wettability between the metal phase and the ceramic phase.