Abstract: In order to investigate the cavitation mechanism under the effect of ultrasonic honing, based on the superposition principle of fluid velocity potential, the dynamic model of double cavitation bubbles in the grinding area was established with considering ultrasonic honing velocity and honing pressure. The effects of initial cavitation bubble radius, double cavitation bubbles distance, ultrasonic acoustic pressure, honing pressure and honing rotation speed on cavitation bubble dynamics in the grinding area were simulated numerically. The results indicated that considering the interactions between double cavitation bubbles, it can acquire obvious cavitation effect when the initial radius ratio of two bubbles was controlled to be less than 3 (or was less than 3). A higher ultrasonic acoustic pressure and lower honing pressure obtained can also perform a better cavitation effect when the difference among ultrasonic acoustic pressure, honing pressure and fluid static pressure was in the range of 0.66MPa to 1.89MPa. Increasing the honing rotation speed can lead to slightly decrease the duration of the cavitation bubble collapse. The numerical results were well verified indirectly by experiments that the surface roughness of the material was measured to describe the cavitation effect of ultrasonic honing.