<p indent=0mm>With the rise of 5G and VR, the demand on visualizing large-scale BIM scene on mobile web browsers is increasing rapidly. However, due to the weakness of browser rendering and networking delay, it is still rather challenging to access huge Web3D scenes smoothly. Firstly, edge computing is introduced into WebBIM online visualization, and a cloud-edge-browser (CEB) collaboratively multi-granularity WebBIM framework is designed. Secondly, the interest degree is defined for each of BIM components and the multi-granularity WebBIM transmission scheduling is proposed based on interest degree. Then, the optimal viewpoint selection for initial loading is presented in terms of globality of viewing scope, light weightness and interest degree. Finally, the experimental platform is deployed using Alibaba Cloud service, and some large-scale BIM scenes are used for practical transmission testing. Experimental results show that the proposed algorithm can effectively reduce the data amount of loading WebBIM scenes. The initial loading speed is also improved significantly, and there is no obvious delay to occur when users move huge WebBIM scenes through freely.