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 .