From Beijing Wudaokou/Chengfu Road to the Niujie Mosque.

As I know, there is no direct bus, but you can make a transfer. First, you need to walk eastwards along Chengfu Road to Wudaokou Bus Stop, and then you may take bus no.508 to Jishuitanqiao South Bus Stop. Afterwards, you can transfer bus no.88 to Niujie Mosque Bus Stop. You can find the mosque on the opposite road.