The frequency calculation on the intermittent disturbance is of importance for the penetration calculation of the escaping jet and the design of anti-shaped charge jet. A physical model was presented based on the analysis of interaction process. The effects of north atlantic treaty organization (NATO) angle and the plate velocity on the disturbance frequency were discussed and compared with experimental results. Results show that the disturbance frequency increases drastically when the NATO angle changes from 40° to 60°, and increases with the plate velocity.