The 46-year-old actor shared a picture on Instagram of the aftermath.
"I'm good.#thanksforsupport ... Had a little accident on set. Haha ! Back at work asap," he captioned the photo.
"Pays to have a thick skull when an iron bar falls on your #head!! busting it open severely also broke my nose in two places. Haha. I got a free nose job out of it... Stoked to be alive," Purcell wrote.
The star was shooting in Morocco when a piece of the set was dislodged and struck him on the head.
The "Prison Break" event series is set to premiere in 2017.