The invention relates to a bone-supporting type mandibular tractor guide plate device and a manufacturing method thereof, which comprises a guide plate body, wherein the inner surface of the guide plate body is matched with the surface contour of the mandibular angle region of a patient, a truncated bone groove and a fixing hole are formed in the guide plate body, the shape and the position of thetruncated bone groove are formed according to the direction and the position of the truncated bone line which is determined during an operation, and the distribution of the fixing hole on the guide plate body coincides with the mounting hole of the tractor. The manufacturing method comprises the following steps of: carrying out three-dimensional model reconstruction on the mandible of the patient; carrying out three-dimensional pre-bending on the tractor model to determine the position of the truncated bone line; designing the guide plate body according to the surface contour of the mandibular ramus and the mandibular angle region of the mandible model of the patient; designing the fixing holes on the guide plate body according to the installation hole position of the pre-bending tractormodel; designing the truncated bone groove on the guide plate body according to the determined position of the truncated bone line; 3D-printing the finished product. The device is simple in structureand convenient to operate, and can improve the accuracy of determining the truncated bone line and positioning and fixing the tractor.