Is there airport shuttle bus service from Beijing Capital International Airport to Nanyuan Airport?

There is no airport shuttle bus service between the Capital airport and the Nanyuan Airport.
If you want to reach directly, you can take a taxi directly.
If you do not mind, you may try to transfer. You can take the airport shuttle bus line 2 from capital airport to Xidan and then take the Nanyuan Airport - Xidan Line to Nanyuan airport easily.