The 34-year-old's deal is the third short-term contract he has signed since joining the Championship club last summer after four injury-plagued years.
Barker only made five substitute appearances, but helped the Brewers avoid relegation and boss Nigel Clough sees him as a valuable squad member.
"I am not signing as a player expected to play 90 minutes or a couple of games a week," Barker told BBC Radio Derby.
"Six months is perfect. Physically I feel no different than I did in my mid-20s. I am fit enough and can still do sessions like everyone else. But I have a reaction with my knee so have to be careful."
The former Derby County centre-back said his aerial ability means both he and Clough are sure he can continue to contribute.
"There is definitely use for me in certain games," Barker added. "To play 90 minutes is a little bit too much, but you never know.
"If pre-season goes well and I am fit and able that would be lovely, but it is not something the gaffer and me are expecting."
Defender Shaun Barker has signed a new six-month contract with Burton Albion.