The man, Chang Suibin, was pulled from under the vehicle after more than 20 people rushed over to lift it up.
A local traffic police officer, Tang Xiaoqi, spotted the incident and waved over at others to help.
He said: "People nearby, passengers from the bus and pedestrians waiting at the traffic lights by this intersection all came together to lift the bus.
"We failed at first, but then more people joined in - some lifting and some pulling the victim - and eventually we got him out."
Chang suffered a pelvic fracture in the accident.
He said: "My sincere thanks to everybody, to the friends, to the kindhearted people of Zhengzhou.... Good people can be found everywhere in our society."