Taxi or bus or train from Beijing Capital airport to Dongcheng district near Wangfujing?

It takes about 40-50 minutes by taxi from Beijing airport to Wangfujing area and the taxi fare is around CNY120 at midnight. From 23:00 to 05:00 the taxi fare is surcharged.
The last express train departs at 22:30 from Dongzhimen to the airport.
After midnight, you can take the airport shuttle bus line 2 to Xidan and then take a taxi to your destination near Wangfujing. It is generally safe either by taxi or shuttle bus around midnight in Beijing.