Hi
There is presently no way to disable this feature.
If you would like Apple to consider adding that option, you can suggest it here:
https://www.apple.com/feedback/watch.html
It may help to wear your watch:
- A little higher on your wrist.
- More tightly (it may otherwise move closer to your hand during daily wear).
- Rotated by 180 degrees and/or on your other wrist, where the buttons may be less likely to be activated unintentionally.
- To adjust the display settings, on your iPhone, in the Watch app, go to: My Watch > General > Watch Orientation - choose the wrist and side for the Digital Crown.
- How to change bands over (if you wish to switch your band around if changing the orientation of your watch):
- Change your Apple Watch band - Apple Support
