How do I get from HKG Airport to Shantou by high speed train ?

I am sorry that there is no direct train service between the two. You may take bus line A11 from Airport (GTC) Station to Macau Ferry, Connaught Road Central Station. The bus fare is HKD 40, and the trip takes about 45 minutes. Then, take a bus to ST from Central Police District Headquarters. The buses depart at 9:00 and 15:00, and the fare is HKD 260. The trip takes about 5 hours. :)