Promising application of high intensity focused ultrasound (HIFU) has been shown in the field of clinical treatment of tumors, but the effects of cavitation have not been considered in current treatment plans. In this paper, the impact of cavitation effects on the tissue lesion in HIFU therapy in vitro is discussed. Firstly, the KZK nonlinear equation and the Pennes biological heat transfer model are used to theoretically simulate the tissue lesion caused by the HIFU thermal effect with different ultrasonic excitation parameters. Then in the experiments, we change the pulse lengths and sound pressures to compare the tissue lesion experimentally and theoretically. Finally the B-type imaging system is used to quantitatively monitor acoustic cavitation, so as to quantitatively analyze the effects of cavitation on the tissue lesion, thus providing better guidance for the design of HIFU treatment.