Can my husband close our joint checking account & file bankruptcy without my knowledge?

Legally, there is no requirement that a spouse notifies his or her partner in filing bankruptcy. On a social level, if your communication is so bad that your spouse would even consider bankruptcy without telling you first, your marriage is already dead, you just don't know it yet.

A spouse does not need to let you know about filing bankruptcy nor is your permission required for him to act. Sort of a sorry reflection on the state of your marriage. And joint accounts allow either person on the account to take out all of the money, so his right to close out the account is also a no-brainer.

Well he can. Is it lawful however? Not in a community/marital property State. Consult an experienced lawyer skilled on both BR and bankruptcy.