Unless you have a court order in place that prohibits this, yes he can come back.  Typically, unless there is some threat of harm, you cannot keep either spouse out of the marital residence.

Right now you need to consult with your divorce attorney in your area as to this.

The marital home is still considered partially his until a court rules otherwise. Therefore, you cannot keep him out of a house that is partially his without a court order. And if you change the locks to keep him out, then you could potentially get in trouble for doing that. However, if he is harrassing you or threatening you or removing items from the house wrongfully, then it is possible to get temporary exclusive use and possession of the home by filing a motion with the court or a restraining order if he is threatening you.

If you would like to discuss your matter further, please contact my office for a free initial telephone consultation. During the consultation, we can discuss your potential rights and options in more detail.