Provided in embodiments of the present invention are a method and device for transmitting a high-definition video signal, comprising: isolating from the high-definition video signal a brightness signal and a chrominance signal, and, by using an analog signal transmission mode, using non-overlapping frequency hands to transmit respectively the brightness signal and the chrominance signal. The solution of the present invention employs the analog signal transmission method, utilizes independent frequency bands to transmit respectively the brightness signal and the chrominance signal, and ensures that the brightness signal and the chrominance signal do not affect each other, thus ensuring video quality and timeliness of the high-definition video signal when transmitted over a long distance.