【Abstract】 Objective To evaluate the application of modified digital guide plate in precise treatment of old zygomatic arch fractures. Methods 27 patients with old zygomatic arch fracture were randomly divided into three groups. Group A was treated with preformed titanium plates and modified digital guide plate, Group B with preformed titanium plates only and Group C with surgical treatment based on the experience of surgeon. The criteria for judging the curative effect were divided into three grades: Good, Medium and Bad. The postoperative effects of three groups were compared. Results The operation time of group A was shorter than that of group B, and the operation time of group B was shorter than that of group C (P＜005). The proportion of good effect of group A was higher than that of group B, and The proportion of good effect of group B was higher than that of group C (P＜005). The proportion of bad effect of group A was lower than that of group B, and The proportion of bad effect of group B was lower than that of group C (P＜005). Conclusion The postoperative effect of old zygomatic arch fractures assisted by digital surgery is significantly better than that of the surgery based on the experience of surgeon. The modified digital guide plate has a significant advantage over the traditional surgery in the treatment of old zygomatic arch fractures. It shortens the operation time and accurately converts the preoperative design into the real surgery, which realizing the purpose of precision treatment.