Background  Military training injury (MTI) is an important factor affecting the health of officers and soldiers, and weakening the combat effectiveness of troops. However, there is still a lack of large sample investigation and research on the occurrence of MTI in a certain system of troops.

  Objective  To analyze the characteristics and regularity of MTI in a certain system of troops in recent 5 years, and provide reference for optimizing MTI protection countermeasures.

  Methods  Based on the MTI data from 2015 to 2019 collected by a certain military medical service statistical system, a comprehensive evaluation was made from the aspects of basic information of the personnel, distribution of disability levels, classification of injury types and injured parts, and monthly distribution of MTI.

  Results   A total of 3 712 cases of MTI occurred from 2015 to 2019. The largest percentage of MTI (60.75%), occurred in the 21-30 years old group, and the military sergeants were involved most frequently (51.56%). During the 5 years, there were 2 628 cases had bone and joint injury (70.80%), 944 cases had soft tissue injury (25.43%), and 140 cases had organ injury (3.77%). Fracture accounted for the largest proportion(43.38%) of the bone and joint injuries, followed by meniscus injury (21.69%) and lumbar disc herniation (13.51%). Ligament injury was the most common type of soft tissue injuries(79.77%), followed by tendon injury (14.41%). The most common organ injuries were ear injury (42.14%) and eye injury (19.29%). In terms of injury site, the proportion of lower limb injury was highest (55.39%), followed by upper limb injury (24.62%) and trunk injury (16.38%). The top 3 injury sites of lower extremity were knee joint (61.53%), ankle joint (19.21%) and femur (6.03%). Shoulder joint (38.18%) was the most common in the upper limb injuries, while lumbar spine (90.13%) were the most common in the trunk injuries. March-May and October-December were the peak periods of MTI, accounting for 27.75% and 29.58%, respectively.

  Conclusion  MTI are common among young male sergeants, mainly including bone and joint injuries, and fracture is the main manifestation. Most of the injuries involve the lower limbs, especially the knee joint. March-May and October-December are the periods of high incidence of MTI.