Diddy says the feds have him all wrong and he's just an innocent man ... because he's pleading not guilty to a couple new charges against him.

The Bad Boy Records founder appeared in court Monday in Manhattan for his arraignment on two new charges ... one for sex trafficking by force, fraud or coercion, and another for transportation to engage in prostitution ... a couple things he says he definitely didn't do.

Feds tacked on the charges in a recent superseding indictment ... the third one we've seen so far in the Diddy case. Diddy showed up in court today with white hair and a short beard, and pled not guilty to the superseding indictment charges.

Prosecutors say the new charges stem from allegations against Diddy from 2021 to 2024 and relate to an individual the feds simply refer to as "Victim-2."

Diddy is now facing 5 criminal charges overall ... two counts of sex trafficking, two counts of transportation to engage in prostitution, and one count of racketeering ... and he's pled not guilty to all charges.

Diddy's legal team has previously described the two alleged victims in the case as former girlfriends ... and they've already essentially referred to "Victim-1" as being Cassie.

Jury selection for Diddy's upcoming trial starts May 5.