Ex wife locked out of house

Can I legally lock my soon to be ex-wife out of the house that we both own. Our divorce is in court right now and I am afraid that she is coming over to the house when I am not there and taking marital property. She has been staying with her parents for a year now.

You need to consult with the matrimonial attorney handling your case. If you don't have one you need to hire one. The house may very well be marital property and she may have as much right to be there as you. Her view, however, it differs from reality, may be that she is taking marital property to protect it from you. Talk to a matrimonial attorney.