Comforters are machine washable so it's safe to wash comforters in your washing machine.
However it's best to wash the comforter in a large commercial sized washing machine to allow the comforter room to move around.
If you wash your comforter at home in your washing machine it's best to do so in a front load washing machine without the agitator.
But if possible take the comforter to a laundromat for best results and to reduce the risk of damaging your comforter.