An ultrasonic osteotome bit, comprising a bit body (1), a bit bar (2) and a bit tip (3). One end of the bit bar (2) is connected to the bit tip (3), and the other end of the bit bar (2) is connected to the bit body (1). The bit tip (3) is of a prism or substantially prism structure with the cross section of a polygonal structure, and the bit tip (2) has at least two cutting faces of different cutting widths. The bit is provided with a liquid flow hole (41), and the bit tip (3) is provided with a knurled structure that extends from a foremost end face of the bit tip (3) towards the bit bar (2) to form a file-type bit. The ultrasonic osteotome bit not only meets the requirement of a surgeon for the accuracy of bone cutting width, but also saves the time required to replace bits of different widths, thereby improving the surgical efficiency.