Pearce is a free agent having been released by Notts County this summer.
The 23-year-old played 18 times on loan at Barnet last season and has also had loan stints at Scunthorpe and Port Vale in clocking up his 151 senior appearances.
"I'm someone who enjoys defending. My first thought on the day of a game is about keeping a clean sheet," Pearce told the club's official website.
"It is obviously going to take a bit of time to gel with the squad but I'm hoping to do that as quickly as possible. Like all players, I want to get in the team and play well.
"It will be important for me to strike up a quick relationship with the other centre-backs here and Aaron Downes is probably the person I've spoken to more than anyone else, so I'm guessing that's a good start.
"As a team, the play-offs are a realistic aim for us and if we get that far then anything can happen.
"I remember being the underdogs when I was at Scunthorpe but we managed to win the play-offs."