The present invention discloses a lateral grinding drill with continuously variable angle, including a tube body component and a grinding head arranged at the front end of the tube body component, the grinding head being configured to be driven to pitch and rotate on its own axis, the tail end of the grinding head is articulated to the inner tube body along the circumferential direction in a form of transmission, and a flexible transmission part is arranged at least on the front end of the inner tube body, which is configured to be articulated to the tail end of the grinding head and be able to transmit torque. The present invention adopts a direct articulated structure to transmit the transmission between the inner tube body and the grinding head, and can implement pitching motion. A flexible transmission structure is used to compensate the axis deviation caused by the pitching and driving. The transmission structure is simple, and the transmission cycle is short, which facilitates stable control to improve the efficiency of the surgery. In addition, with the structure which can adjust the grinding head in both the pitching and circumferential positions, it achieves the universal direction adjustment of the grinding head, which can have a good adaptability for the surgery position and good accuracy to improve the efficiency in surgery operation, and shorten postoperative recovery time, to alleviate the suffering of the patients while reducing treatment cost.