Disclosed are a method and a system for intercepting fraud phones in real time during calling. The method includes that when a call made by a calling user is triggered to a service control point (SCP) through a calling mobile switching center (MSC), the SCP instructs the calling MSC to perform call proceeding, so that the calling user and the called user are in voice communication; meanwhile, a fraud prevention platform acquires messages received by the SCP in real time, whether the calling number contains in an intercept number table or not is judged when the call, made by the calling user, received by the SCP is recognized, if so, then a called visitor location register (VLR) is instructed to remove the voice channel between the calling user and the called user after the calling user and the called user are in voice communication, otherwise, the process is ended. The method and the system belong to the technical field of network communications and can realize real-time interception to the fraud phones without any adjustment of existing networks.