With the advent of WebRTC technology, the solution of real-time audio and video processing was provided. Its open standards provide a technical basis for the further research of real-time audio and video processing. Through the research of the core audio and video operation library of the WebRTC, we apply the technical solutions of WebRTC in the online interrogation module of the post-diagnosis medical service system, to improve the quality of the audio and video of online consultation service. Through analyzing the communication of the core audio and video of the WebRTC and depending on the real-time communication architecture of WebRTC protocol, we design the scheme of signaling agent and media agent, and finally realize the real-time communication of the post-diagnosis medical service system.