A system for implementing media interaction of IPTV, comprising: a content delivery network manager, a content delivery network agent, a center stream media server, a edge stream media server, and a user terminal, wherein, the content delivery network manger and the center stream media server are connected to a router of a metropolitan/wide area network, the edge stream media server is connected to a edge router through which the metropolitan/wide area network connects with an access network to form a peer-to-peer area (P2P area) of a server side, wherein, peers of the P2P area of the server side comprise the center stream media server and the edge stream media server; the content delivery network agent is connected to the edge router to which the edge stream media server connects, the user terminal connects to the edge router to which the edge stream media server connects via the access network to form a P2P area of a terminal side, wherein, peers of the P2P area of the terminal side comprise the edge stream media server and the user terminal; wherein the user terminal is adapted to send a request for a TV On Demand (TVOD) media file or a Time Shift TV (TSTV) media file to a edge stream media server of the edge P2P area in which it is located, and play the first data block of a target media file immediately when receiving the first data block of the target media file; at the same time, the user terminal is further adapted to request, from the content delivery network agent in the P2P area of the terminal side in which it resides, an information list of content delivery network nodes capable of providing subsequent data blocks of the target media file, and sequentially request nodes in the information list to download the subsequent data blocks of the target media file according to the received information list, then play downloaded data blocks sequentially; the center stream media server which comprises a sub-center stream media server is adapted to store segmented media data, and send different data blocks of the segmented media data to different edge stream media servers and store them thereof according to a content release policy; the edge stream media server is adapted to store the data blocks sent by the center stream media server; when receiving the request for a TVOD media file or a TSTV media file sent by the user terminal, the edge stream media server is adapted to send the first data block of the target media file to the user terminal according to the request; and the content delivery network agent is adapted to perform statistics and management operation on media data distribution in the P2P area of the terminal side, and return to the user terminal the information list of the content delivery network nodes capable of providing the subsequent data blocks according to the request of the user terminal, wherein, the information list comprises the edge stream media server and/or a user terminal capable of providing the subsequent data blocks; wherein, when the content delivery network agent can not find the content delivery network nodes capable of providing the subsequent data blocks of the target media file in the P2P area of the terminal side in which it resides, the content delivery network agent is further adapted to notify the edge stream media server to download the subsequent data blocks of the target media file in the P2P area of the server side; the edge stream media server is further adapted to request to download the subsequent data blocks of the target media file from the content delivery network manager in the P2P area of the server side according to a notification of the content delivery network agent; and the content delivery network manager is adapted to perform statistics and management operation on media data distribution in the P2P area of the server side, and return to the edge stream media server the information list of the content delivery network nodes capable of providing the subsequent data blocks of the target media file according to a request of the edge stream media server, wherein, the information list comprises the center stream media server, and the edge stream media server capable of providing the subsequent data blocks.