Abstract: Steel truss trestle is an important material transportation structure in coal mines and other enterprises, which has the characteristics of good force performance, rapid construction and convenient demolition. Sprinklering and poor maintenance within the trestle may cause the bridge rod to corrode or weaken its bearing capacity, or even collapse. The study of such typical accidents can reduce the associated losses. In this paper, a trestle collapse accident was investigated and analyzed in detail.First of all, the collapse of the trestle and the existence of damage or defects were investigateed, and component size, material strength, tilt, corrosion and surface thickness of the corresponding were tested as well. The actual load of the structure was considered and the rod damage was taken into account to obtain the safety margin of the structure. Considering the results of investigation, detection and calculation analysis, the detailed process of trestle collapse and the main cause of bridge collapse were obtained, and the safety of the affected bridge structure were analyzed. On this basis, it was proposed to strengthen the abdominal rod, add stent and other targeted reinforcement treatment methods to ensure structural safety.