More than 70 disasters occurred on various sections of the railway, which links the city of Baoji in Shaanxi Province with Chengdu, the capital of Sichuan Province, on July 16 and 17, after heavy rainstorms lashed Baoji, Xinhua news agency reported.
The Anhe Bridge, a section of the railway, was brought down by the floods on July 17.
Following the disasters, all train services on the railway were cancelled or diverted to other routes for 25 days till Saturday.
China Railway Xi'an Bureau Group Co., Ltd. launched an emergency repair operation, dispatching workers and sending excavators, cranes and other types of large machinery to fix damage to the track.
The railway was put into operation in 1958, becoming the country's first electrified railway. Winding through mountains, it has a designed maximum speed of 80 kilometres per hour and serves both freight and passenger trains.