I lost my ID card. Can I use my social security card to prove it by train?

The social security card can't be used to take the train, but it can be used in temporary id card.

Extended data

The valid documents recognized by the railway department are:

Temporary id card, household registration book, military officer's card, military security card, armed police officer's card, soldier's card, military cadet's card, military retired cadre's card, Hong Kong and Macao residents' pass to and from the mainland, China people's pass to and from Hong Kong and Macao, mainland travel permit for taiwan residents, foreigner's residence permit, foreigner's entry and exit permit, consulate card, diplomat's card, passport, and foreigner's identity certificate issued by the Ministry of Foreign Affairs.

The temporary identity certificate of passenger train issued by railway police authorities can be handled free of charge at the certificate-making window of the public security department next to the ticket office of the railway station, and can only be used as the proof material for boarding.

reference data

Baidu Encyclopedia-Regulations on the Administration of Railway Vehicles