Embodiments of the present invention disclose an apparatus for transmitting video/audio data, including a receiving decoding module, configured to receive remote video/audio data and a stream media transmitted from an IP network, respectively decode the received remote video/audio data and the stream media, input the decoded video data to the video synchronization module, and input the decoded audio data to the mixer; a video synchronization module, configured to combine and a synchronize the received video data; a mixer, configured to mix the received audio data. Embodiments of the present invention also disclose a network device and a method for transmitting video/audio data. Through the technical scheme disclosed in the embodiments of the invention, a user terminal may make an audio/video call while watching a stream media program via the same display screen and speaker.