Abstract: Objective To explore MRI findings of triceps surae sports injury and diagnostic value of MRI in triceps surae sports injury. Methods Twenty-eight patients with triceps surae sports injury who were treated in Surgical Department of the Northern Theater Air Force Hospital from January 2017 to June 2019 were enrolled. Within one week after symptoms occurrence, MRI and ultrasound examination were performed. The images of MRI and ultrasound examination were analyzed. MRI features of triceps surae sports injury were observed. The detection rates of MRI examination and ultrasound examination were compared. Results A total of 35 muscles were injured in 28 patients, among which 17 were mildly injured, 13 were moderately injured and 5 were severely injured. MRI findings showed mild injury with normal tendon morphology, moderate injury with partial tear, and severe injury with complete tear. There was interfascicular exudation in all the injured muscles, no broken end exudation was observed in mild injury, superficial fascia exudation was found in 47.06% muscles, superficial fascia exudation and broken end exudation were found in all the moderately injured and severely injured muscles. Compared with ultrasound, MRI had a higher detection rate of triceps tears in the lower leg and a lower detection rate of triceps injuries in the lower leg. The differences were statistically significant (P<0.05). However, there was no statistically significant difference in the detection rate of intramuscular effusion and fascia injury between the two groups (P>0.05). Conclusions Both ultrasound and MRI have higher detection rates for triceps surae sports injury, but the latter was more accurate in reflecting the position, degree and type of triceps injury in the lower leg.