The main structure of the 9,077-meter Guanting Reservoir bridge, part of the Beijing-Zhangjiakou high-speed railway, was completed on Tuesday.
The bridge stretches over the Guanting Reservoir in Huailai county, North China's Hebei province.
It is China's first bridge for high-speed trains with a maximum operating speed of 350 kilometers per hour to run on.
The Beijing-Zhangjiakou high-speed railway, a major transportation project for the 2022 Winter Olympic Games, is expected to be finished by the end of 2019.
It will cut the commuting time by train between Beijing and Zhangjiakou to about an hour from more than three hours.