Audrina Patridge's estranged husband, Corey Bohan, is off the hook with Orange County prosecutors when it comes to domestic battery ... TMZ has learned.

The D.A.'s Office says it will not prosecute Bohan based on the report Audrina made to cops after a Sept. 6 incident. As we first reported ... Audrina claims Corey verbally belittled her and her mother, and snatched her phone out of her hand while she was recording his rant.

Despite her claims, the D.A. says there was not enough evidence to go forward with prosecution. 

While Bohan might be off the hook with OC prosecutors, we're told the domestic violence restraining order still stands.