I want to create blender add-on using QT framework, but couldn't find any information about how install it in Blender. I would be grateful for any information!
Either unpack the PySide/PyQt folder(s) to Blender's
You should then be able to
import them normally.
Or install them to add them to your system's python installation and use
sys.path.append() in your script to add the required folders to Blender's module search path temporarily and
import as usual.