Tailings dam is a key facility for the mining process, which is also the major hazards for the surrounding environments. It could cause catastrophic accidents and severe personal injuries if the tailings dam failed. The occurrence of tailings dam accidents will greatly damage the life and property of the people in the surrounding areas and damage the ecological environment around the region. In recent years, Chinese government has introduced policies to step up investigation and management of mine tailings potential hazards and results in great achievements. However, a large part of the tailings dam still has prominent safety problems due to long-term site selection, design, system construction and management. Flood drainage system plays an important role both in the mining process and in the tailings dam safety. Through the analysis of the causes of tailings dam accidents, this paper discoveries that a number of accidents caused by the failure or damage of flood drainage facilities, and the risk in flood season is especially prominent. The safety hazards detection of the flood drainage is vital to secure the tailings dam safety. A safety hazards detection system based on 3D panorama technology has been achieved in this paper. It provided a new way to detect the safety hazards remotely on portable devices. Firstly, the 3D panorama data acquisition device was designed and developed. The functions and requirements of 3D panorama data acquisition device were investigated according to the actual environment of flood culvert. The structure and hardware of the device were calculated according to the target functions. Three-dimensional environment image data for rapid acquisition, and the use of feature matching and optical flow principle of the collected images were spliced to generate a 3D panoramic image of flood drainage of tailings dam in mining. The safety hazards detection system includes 3D panorama client and panorama images cloud database. It has five layers which are basic configuration layer, interface presentation layer, data management layer, function module layer and background management layer. The functional module layer has five functional modules, including mine personnel management module, tailings pond panoramic scene module, culvert potential danger detection module, interface menu navigation module and material information management module. It can help safety inspectors to detect and investigate potential safety hazards in flood drainage culverts, which would strengthen the safe operation of tailings dam and maintain the safe and sustainable production of mines. This system has been applied to the tailings dam of a mine to collect 3D environmental image data of the flood drainage culvert. The panoramic image is spliced to generate a panoramic view through the cloud platform. The results show that this system can be used in mine drainage culvert safety hazards detection.