Abstract: To address the challenging machinability of TC4 titanium alloy caused by its self-passivation characteristic, this study proposes a novel high-intensity focused ultrasound (HIFU)-assisted electrochemical machining process. Experiments were conducted using COMSOL Multiphysics finite element software to establish a temperature model of the focused ultrasonic field and simulate the temperature rise characteristics of the focal region over time. Meanwhile, K-type needle thermocouples and surface-mounted thermocouples were employed to experimentally measure the temperature rise at the focal point. A comparison of the experimental results from three processes-conventional electrochemical machining, thermally assisted conventional electrochemical machining (with elevated electrolyte temperature), and HIFU-assisted electrochemical machining-revealed that the simulated temperature rise at the focal point of the focused ultrasound was approximately 50 ℃ with clear strong-focusing behavior. The actual measured temperature rise in the focal region reached 70 ℃, and infrared thermography also showed a similar strongly focused distribution trend. The temperature variation trends observed in simulation and experiment were highly consistent. Furthermore, HIFU-assisted electrochemical machining significantly improved machining efficiency, the micro-hole diameter obtained by conventional ECM was 1000 μm, while under HIFU assistance, it was reduced to 500 μm, indicating that the acoustothermal effect of focused ultrasound markedly enhances the electrochemical machining process.