The work aims to explore the main factors affecting the distribution of impact force during ultrasonic shot peening, and verify the feasibility of changing process parameters to control the strengthening area of the target part. The finite element model of TC4 titanium alloy by ultrasonic shot peening was established. Convergent chamber and cylindrical chamber were established to study the effect of energy distribution in different chambers on impact force distribution during ultrasonic shot peening. The energy input was controlled by changing the amplitude of the vibration to study the influence of energy input on impact force distribution. The simulation of ultrasonic shot peening was carried out for two chambers under the amplitude of 60 μm, 80 μm and 100 μm. With the increase of energy input, the value and distribution area of the impact force increased. For the cylindrical chamber, the USP test under three kinds of energy input was carried out, and the obtained coverage was 10.23%, 31.23%, and 56.98%, thus the effect of ultrasonic peening energy input on the impact force was verified. The convergent chamber had more obvious strengthening effect on the middle target area of the test piece under the same energy input. During USP, the strengthening range and intensity of the target area of the parts can be controlled by changing the shape of the chamber and the amplitude of the vibration head.