You might be on a network that is blocking the Tor network, and so you should try using bridges. Some bridges are built in to Tor Browser and requires only a few steps to enable it. When you open Tor Browser for the first time, click "Tor Network Settings". Under the "Bridges" section, select the checkbox "Use a bridge", and choose the "Select a built-in bridge" option. From the dropdown, select whichever pluggable transport you'd like to use. Once you've selected the pluggable transport, scroll up and click "Connect" to save your settings.

Or, if you have Tor Browser running, click on "Preferences" (or "Options" on Windows) in the hamburger menu (≡) and then on "Tor" in the sidebar. 在“网桥”界面中，点击“使用网桥”的复选框，并从“选择一个内置网桥”选项中，在下拉菜单里选择任意一个您想要使用的可插拔传输。 当你关闭标签页时你的设定会自动保存。

如果您需要其他的桥接，你可以从桥接网站 上查询。 关于网桥的更多信息请参阅 Tor 浏览器用户手册。