from PVG TO Shanghai south railway station, how?

The subway line 2 will stop at around 22:00 and the last bus line 7 to the South Railway Station is at around 23:00.
If you hurry up, you may catch the last bus of airport shuttle bus line 7 to get to the south railway station directly.
If you miss the last bus, you can take the shuttle bus night line to get to the terminal at Hongxu Road and then take a taxi to the south railway station.