The former Toro Rosso racer moved into the role after losing his seat with Red Bull's junior team at the end of 2011.
Buemi will conduct extensive simulator work as well as being on hand to stand in for Sebastien Vettel or Mark Webber if needed.
"I know everyone at Red Bull Racing well and it's good to remain with the team for another year," said the 24-year-old Swiss driver.
"Of course my aim is to be driving at the races again, but I am still learning all the time from my work with the team.
"I help with the development of the car and provide feedback throughout the season, both at the factory and at races."
Alongside his Red Bull duties in 2012, Buemi also took part in the Le Mans 24 Hours as part of the Toyota LMP1 squad.
