Michael Madsen has officially filed to divorce his wife ... claiming he's been the victim of her abuse for years -- and saying he believes she drove their son to kill himself.

The actor filed the divorce petition Wednesday ... citing irreconcilable differences in the doc -- and, claiming he actually separated from his estranged wife, DeAnna Madsen, back in January 2022.

Although he checked the irreconcilable differences box, Madsen also included a statement with the petition ... saying it goes far beyond simply no longer seeing eye to eye.

MM says he separated from his wife back in '22 because he believes "her neglect, drinking and alcoholism," drove their son Hudson to take his own life.

Madsen adds that DeAnna -- who he married back in 1996 -- contributed to his own issues ... putting him in an "abusive, co-dependent, and toxic relationship" which he says ended with his wrongful arrest for domestic violence last month.

As you know ... Madsen was arrested last month on a misdemeanor domestic violence charge after cops said he shoved DeAnna. He posted a $20k bond not long after.

However, the following week, the L.A. County District Attorney told us they wouldn't file charges due to insufficient evidence. Now, on top of the divorce, Madsen's also seeking a domestic violence restraining order of his own.

Madsen's rep told us at the time he was happy his client could put the arrest behind him ... and, now it looks like he's doing the same with the marriage.

Michael's management and publicist declined to comment further. We reached out to DeAnna ... so far, no word back.