The construction took place at the Nanlong Railway Station in Longyan, Fujian Province
The project was finished so quickly because the workers had been arranged into seven units to tackle different tasks simultaneously, said Zhan Daosong, a deputy manager at China Tiesiju Civil Engineering Group, the country's main railroad builder.
The construction of the Nanlong Railway is ongoing and is expected to complete at the end of 2018.
Measuring 246 kilometres (152 miles) in length, the railway is due to be a main transport link between south-east China and central China, Xinhua reported.
The railway would be able to support trains which operate at a maximum speed of 200kmh (124 mph), according to reports.