Video shows the flightless bird, which can reach speeds of 45 miles an hour, swerving cars as it races across lanes on the Rongcheng–Wuhai Expressway in Tianjin on January 3.
A witness called traffic officers to say an ostrich 'as big as a car' was rushing down the highway.
Ostriches can grow as tall as 9 feet and weigh up to 330 pounds - enough to do severe damage in a collision with a car.
They herded it into an enclosed courtyard, where it was reunited with its owner.
He had been transporting the ostriches to Jizhou District when a door bounced open when he hit a bump. The bird then made its break for freedom, according to local news site Sina.