Objective: To explore the clinical effect of screw locking and fixed guide template assisted with transverse lengthened sacroiliac screw insertion in the treatment of unstable pelvic fractures. Methods: The data of 44 patients with unstable pelvic fractures treated in the Orthopedic Center of the Fourth People's Hospital of Zigong from July 2020 to July 2022 were retrospectively analyzed. Twenty-five patients were treated with rotary locking guide plate for reduction and fixation (guide plate group), and 19 patients were treated with traditional fluoroscopic nail placement (perspective group), and comparison of perioperative and imaging of two groups of information. Results: All patients were followed up from 18 months to 24 months (average 20.5 months). No serious complications such as vascular injury and pulmonary embolism occurred in the two groups after operation. Compared with the fluoroscopy group, the radiation time and operation time in the guide plate group were statistically different (P<0.05), but there was no statistical difference in blood loss between the two groups (P>0.05). The excellent and good rates of Majeed score were 92% and 84%,Matta score was 96% and 94% in guide plate group and fluoroscopy group after operation. There was no significant difference between Majeed score and Matta score (X2=0.65；; X2=0.04； P>0.05）； The excellent and good rate of Grade grading in guide plate group and fluoroscopy group was 98% and 79%, and there was a statistical difference in the excellent and good rate of Grade grading after operation (X2=8.53,P<0.05). There were 50 screws and 38 screws in guide plate group and fluoroscopy group respectively, but there was no statistical difference in the length of sacr1 and sacr2 screws between the two groups (P > 0.05). Conclusion: For unstable pelvic fractures, about 2/3 of the patients can have sacral 1 and sacral 2 transverse lengthening screws at the same time. Compared with the traditional fluoroscopic nailing, it is more accurate, less fluoroscopic time, safer and more feasible to apply the screw fixation guide to treat unstable pelvic fractures.