Each time you check-in in the airport counter, they will double check you identity (回鄉証).
Actually, when you book the ticket, they will ask you for your name and id number for confirmation.
If you are Chinese (HK or Macau Resident), you shall apply for the 回鄉Card and which can last for 10 years. Relatively cheaper then you apply for one time visa.
The application process for one time visa and the 回鄉Card actually is the same.