The promo artwork, carrying the tagline "Back for War", sees Sylvester Stallone's Barney Ross front-and-centre of the image with the rest of the Expendables team around him.
Lionsgate will hand out signed collectors' editions of the posters at Comic-Con. 250 limited-edition prints have been produced on speciality canvas paper for the event.
Bruce Willis, Arnold Schwarzenegger, Dolph Lundgren and Jason Statham reprise their roles from the first action blockbuster, while cast newcomers include Jean-Claude Van Damme, Liam Hemsworth and Chuck Norris.
The Expendables 2 opens in cinemas this August.
Watch a new video clip from The Expendables 2 below: