The Charlton midfielder is one of three overseas players named by coach Ratomir Dujkovic.
Zheng will be joined by fellow overage stars, former Chinese captain and defender Li Weifeng and striker Han Peng.
"It is my dream to march into the Olympic final in the Bird's Nest, as the coach has said," Zheng told the Beijing Daily.
"I want to get myself back into top form before the Games. I have been recovering well and I hope all my injuries can heal in the next 20 days," he said.