If you're asking whether your ex-wife can subpoena your bank records after divorce, the answer is maybe. It depends on the state in which you live and the specifics of your divorce agreement.
In some states, financial information is automatically included in the public record after a divorce. That means anyone - including your ex-wife - could request and receive copies of your bank records. Other states allow financial information to be sealed from the public record, which would prevent your ex-wife from accessing your bank records without a court order.
If your state allows financial information to be sealed and you have an agreement with your ex-wife that she will not request access to your bank records, then she likely won't be able to subpoena them. However, if there's no such agreement in place or if her attorney believes she has a good reason to see the records (for example, if there's reason to believe you're hiding assets), then she could attempt to subpoena them.
Ultimately, it's up to the judge to decide whether or not to grant a subpoena for bank records in a divorce case. If you're concerned about your ex-wife being able to access your financial information, talk to an experienced family law attorney in your state for more specific advice.