The invention provides an intraoperative mobile C-arm X-ray machine positioning auxiliary device, comprising: a C-shaped arm, which is arranged on a bracket, and the C-shaped arm can rotate and slide along the bracket; an image receiving intensifier, which is arranged on the bracket One end of the C-shaped arm; emitting X-ray tube, which is arranged on the other end of the C-shaped arm, and above the image receiving intensifier; 4 laser generators, which are equidistantly arranged on the emitting On the circumference of the X-ray tube, the connecting lines of the four laser generators are in the shape of a "ten", the power of the laser generators is less than 5mmw, and the wavelength is 650nm. The intraoperative mobile C-arm X-ray machine positioning auxiliary device provided by the present invention has a simple structure and low cost, enables doctors to quickly and accurately determine the shooting range during the operation, has high precision and good stability, significantly reduces the number of fluoroscopy times, and improves operation safety. Sex, shorten operation time, reduce radiation exposure caused by repeated fluoroscopy, reduce tissue trauma and complications, and reduce radiation damage to patients and medical staff.