Abstract: In practical applications of ultrasonic cavitation, bubbles may be confined within a small enclosed cavity. Under such conditions, the surrounding liquid cannot be treated as an unbounded medium, and the dynamic behaviors of the bubbles are influenced by the cavity walls. This study investigates the dynamics of two bubbles in a spherical cavity based on numerical simulations. The effects of driving sound pressure amplitude and frequency, bubble ambient radii, initial bubble positions, and the size of cavity on bubbles translation and pulsation are systematically examined. The results indicate that increasing the driving sound pressure amplitude accelerates the translational motions of bubbles. Additionally, when the driving frequency is low or within certain optimal ranges, the bubbles also exhibit faster translational velocities. These findings suggest that the manipulation of bubbles within an elastic cavity can be achieved by adjusting the driving ultrasound. Analysis of bubble dynamics under varying cavity dimensions reveals that increasing the outer radius of the cavity affects bubble velocities in a complex manner, but this impact diminishes once the outer radius exceeds a certain threshold. Conversely, increasing the inner radius of the cavity initially enhances the bubble translation speed but subsequently slows it down in general. Furthermore, the initial positions and ambient radii of the bubbles significantly influence their motions. Bubbles that are symmetrically positioned relative to the cavity center and have identical ambient radii exhibit fast approach velocities. This study provides a theoretical foundation for precisely controlling bubble motion in closed environments, and is conducive to promoting the practical application and popularization of acoustic cavitation.