Carbon Fiber Reinforced Polymer （CFRP） exhibits anisotropic mechanical properties and inherently low interlaminar bonding strength，which collectively lead to machining defects during conventional processing，consequently limiting its broader industrial application.Ultrasonic machining，which superimposes high-frequency vibrations onto conventional mechanical processes，has been widely adopted due to its proven capability to reduce cutting forces/temperatures while mitigating machining defects in CFRP composites.This study provides a systematic review of ultrasonic machining technology for CFRP，beginning with an overview of key system components：ultrasonic vibration tool holders，wireless power transmission systems，and ultrasonic power supply units.The material removal mechanisms and defect formation dynamics are analyzed through multiple perspectives，including kinematic characteristics，cutting force fluctuations，and chip formation patterns.Special attention is devoted to the investigation of the root causes，detection methodologies，and ultrasonic suppression mechanisms of typical processing defects such as delamination，burr formation，and tearing.Furthermore，the review systematically summarizes the technical advantages，operational paradigms，and process parameter-effect correlation mechanisms in ultrasonic machining，while projecting future development trajectories.