Embodiments of the present invention provide a method, an apparatus, and a system for implementing picture in picture in a home network. The method for implementing picture in picture in a home network includes: obtaining a video stream of a video main window from a video network and decoding and playing the video stream of the main window; receiving a picture in picture activation signal sent by a user; sending a transcoding request message to a control device, where the transcoding request message carries a number of a picture in picture video sub-window channel; receiving a video stream of the video sub-window channel, where the video stream has been transcoded and then sent by the control device; and decoding and playing the video stream of the video sub-window channel.