Abstract: Aiming at the difficulty of developing a coal mine 3D visualization business system based on Unity3D, based on the analysis of the Unity3D framework and underlying technology, the 3D Web engine is designed and packaged from five perspectives: asset packaging and downloading, 3D scene loading and unloading, scene editing, scene interaction, and Web interface function communication. The asset package packaging and download are studied to solve the problem of data source; using asynchronous loading technology to load the asset package in the browser, realize the data loading and 3D scene construction; encapsulating the commonly used editing functions in Unity3D to enable quick scene editing; encapsulating the mouse interaction and camera control in Unity3D and reuse it in browser 3D scene; according to the principle of Web interface communication, developers can use the mainstream JavaScript language to call the encapsulated coal business function interface, so as to solve the difficult problem of developers developing 3D applications in coal mines. The results show that the development of the mine 3D visualization business system based on the 3D Web engine can reduce the difficulty of development and achieve the purpose of realistic scene visualization.