Abstract: The disclosure provides a method and system for preventing a fraudulent video relay. The method comprises: a video source node slicing a video source and relaying fragments of video data to next nodes; a relay node user receiving a relayed fragment of video data from a previous node and writing a video relay session information into a system; a viewing node establishing a video relay session with the relay node, receiving, reassembling, decoding and playing the fragment of video data, and regularly recording relay behavior data to the system; and a relay reward node regularly obtaining unprocessed relay behavior data, calculating a reward value for each relay user, and writing the reward value into a block-chain system, to implement accurate rewards of relay.