A subway train runs on Line 3 of the Shenzhen Metro (Longgang Line) in Shenzhen city, South China's Guangdong province, Oct 19, 2014.[Photo/IC]

China started to build Asia's longest subway station in Shenzhen on Sunday.

Pinghu Central station is the terminal in the north of Subway Line 10. The Line, with a designed length of 29.2 kilometers, is under construction and scheduled to begin operation in 2020. It will stretch south to the Futian Checkpoint station bordering Hong Kong.

The two-story station is designed to be 22 meters in width and 170 meters in length, the longest in Asia. There are two reasons for building such a long station. One is the expected 20 percent boom in passenger numbers and the other is the extension of trains from six to eight carriages.

Shenzhen has 187km of subway line in operation and another 211km under construction. This year will see three subway lines in trial operation and four will see start of construction.

With the formation of Shenzhen's subway network, Pinghu Central station will become an important transport hub by connecting several lines.