The Steelers have sought offensive line help since right tackle Willie Colon was lost for the season last month with a torn Achilles' tendon.
The Steelers could play the 35-year-old Adams at right tackle, or shift him to his natural position of left tackle and move Max Starks to the right side.
The 6-foot-7, 340-pound Adams played 12 seasons with Dallas, but was cut last spring before receiving a $2.5 million roster bonus. He worked out with the Steelers last month. Two years ago, Adams signed a six-year contract with Dallas that guaranteed him about $15 million.
The NFL Network first reported the Adams deal.