Objective To evaluate the value of X-ray plain film and post-processing technique of CT in the fixation of multiple rib fractures. Methods 100 patients with multiple rib fractures admitted to our hospital from January 2017 to April 2018 were selected to compare the sensitivity, specificity and detection rate of X-ray plain film and CT post-processing technology in the diagnosis of multiple rib fractures. The value of X-ray plain film and CT post-processing technology in the preoperative diagnosis and post-operative re-examination of multiple rib fractures was analyzed. Results The diagnostic sensitivity, specificity and detection rate of X-ray plain film for multiple rib fractures were 73.16%, 68.83% and 85.28%, respectively. The post-processing techniques of CT were 94.80%, 90.90% and 98.70%, respectively. The diagnostic sensitivity, specificity and detection rate of post-processing techniques of CT for multiple rib fractures were significantly higher than those of X-ray plain film(P<0.001). Complete fracture and incomplete fracture have different X-ray manifestations. The patients with pleural effusion were treated with drainage tube. In three-dimensional reconstruction, the location, number, shape and displacement direction of multiple rib fractures could be clearly seen. Fixation of rib fracture was performed according to the three-dimensional reconstruction image of the patient. CT plain scan was performed within 1 to 7 days after operation, and the chest X-ray films were taken after internal fixation of multiple rib fractures. Conclusion CT post-processing technology is superior to X-ray plain film in the diagnosis and detection of multiple rib fractures. Clinically, relevant surgical procedures can be formulated according to the image data, and X-ray plain film is more economical and convenient for re-examination after fixation and removal.