Does the Xiaomi Smart Band 8 have an always-on display function? How to enable it?

It supports Always-on display.
In the band >> [Settings] >> [Display] >> [Always-on display], you can choose to turn on or off the Always-on display function. You can choose to turn on intelligently, turn on at a scheduled time, or turn on all day (start time = end time).
Note:
1. After turning it on, the power consumption of the band will increase significantly;
2. After turning on the Always-on display, the band will always display the exercise status when exercising, and the screen will not be off;
3. The Always-on display style varies for each band display. Please tap on [Manage band displays] to view the Always-on style corresponding to each band display.