You could try looking at https://msdn.microsoft.com/en-us/windows/uwp/get-started/enable-your-device-for-development. It explains a little more of what you get with ‘developer mode’. That page is in english, but there is probably a mandarin version somewhere.
Here are some choice quotes from that webpage as of 2016-08-03:
By default, you can only install Universal Windows Platform (UWP) apps from the Windows Store. Changing these settings to use developer features can change the level of security of your device.
When you enable Developer Mode, you can enable a device for development, or just for sideloading.
Sideloading is installing and then running or testing an app that has not been certified by the Windows Store. For example, an app that is internal to your company only.
Developer mode lets you sideload apps, and also run apps from Visual Studio in debug mode.
If you intend on writing and testing app on the same PC (the most common scenario) you'll need to select Developer Mode.
Note If you sideload apps, you should still only install apps from trusted sources. When you install a sideloaded app that has not been certified by the Windows Store, you are agreeing that you have obtained all rights necessary to sideload the app and that you are solely responsible for any harm that results from installing and running the app.
In addition to sideloading, the Developer mode setting enables debugging and additional deployment options. It replaces the Windows 8.1 requirement for a developer license.
On the desktop device family:
Enable Developer mode to develop and debug apps in Visual Studio. As stated previously, you will be prompted in Visual Studio if Developer mode is not enabled.
On the mobile device family:
Enable developer mode to deploy apps from Visual Studio and debug them on the device.
So, depending on how you look at it, it isn't any more dangerous than the software you install and execute.