Hi @Shaopei,
As other users said we have quite a number of Roon users in China having issues using Roon. Roon relies on connections to upstream services and addresses that might be unreachable due to your geographic location. Please see the suggestion shared by another user via the linked thread below. This situation remains unfortunately beyond Roon’s reach of influence, but there are steps you can take that will likely allow for a successful connection to upstream services such as this post by hx_sion ARC not working: not be able to access Roon server - #8 by hx_sion