Double-bubble ultrasonic cavitation dynamic differential equation obtained from superposition principle is normalized. MATLAB is used to analyse the effects of bubble linearity, double-bubble distance, sound frequency, sound pressure amplitude on cavitation process. Bifrequency ultrasound is introduced into the equation under discussion in this article. The calculation results show that bubble linearity is a main factor, which determines cavitation characteristics. The effect of sound pressure is strongest, and the frequency effect is the next strongest. Double bubble interactions affect cavitation characteristics to a certain extent, which reduces with distance increasing. Bifrequency ultrasound has a limited effect on cavitation characteristics, and it turns biggest when two component pressure amplitudes are equal.