<p>The micro-hole is the signal interconnection channel between the layers of the high-speed printed circuit boards (PCB), and its surface quality is crucial to the signal transmission performance. However, the anisotropy and non-uniformity of PCB laminated composite materials often lead to machining defects such as burr and nail-head effect in micro-hole drilling, which seriously reduce the surface quality of micro-holes. Thrust force is an important indicator to study the surface quality of micro-hole drilling in high-speed PCB. Ultrasonic-assisted vibration drilling technology can effectively improve the surface quality of micro-holes. Therefore, a thrust force model describing the whole process of ultrasonic-assisted micro-hole drilling is established based on cutting edge motion trajectory. In addition, by setting different processing parameters and ultrasonic parameters, 0.2-mm micro-drill bit is used to carry out conventional drilling (CD) and ultrasonic-assisted drilling (UAD) experiments on high-speed PCB. The mean relative error of the theoretical value is 24% and the minimum relative error is 3%. Under high feed rate and high ultrasonic power conditions, the measured average thrust force decreased, while the instantaneous thrust force exhibited a concurrent increase. Furthermore, as the rotational speed increased, the average thrust force initially increased before subsequently decreasing.</p>