Objective To explore the diagnostic value of multi-slice spiral CT (MSCT) in patella fracture. Methods A total of 46 patients with patellar fracture admitted to our hospital from April 2017 to April 2018 were selected. The clinical data of the patients were collected. All the 46 patients underwent CT non-enhanced scanning and image post-processing. The sensitivity and specificity of the diagnosis of patella fracture by CT scanning and post-processing were calculated. Results The sensitivity and specificity of the post-treatment technique for the diagnosis of patella fracture were 97.82%, which was significantly higher than 84.78% and 82.60% of CT non-enhanced scanning. The difference was statistically significant (χ2 =4.929 and 6.035, P=0.026 and 0.014, respectively). Patellar fracture type: there were 6 cases of transverse fracture, 24 cases of comminuted non-displaced fracture, 7 cases of comminuted displaced fracture, 3 cases of vertical fracture, and 6 cases of osteochondral damage. The patellar cortical insufficiency can be observed by CT scanning, most of the fracture fragments are obviously separated, and the volume reconstruction has a strong sense of stereoscopic reconstruction. The patellar three-dimensional structure can be rotated from multiple angles, and the bone continuity interruption, local collapse, visual and clear fracture trace can be observed. Conclusion The sensitivity and specificity of patellar fracture diagnosis with multi-slice spiral CT volume reconstruction is high, which can directly show the interruption of bone continuity, local collapse and fracture trace, and is worthy of clinical application.