A signal extension system is provided according to the present disclosure, which includes: a transmitting side chip and a receiving side chip connected to the transmitting side chip. The transmitting side chip is configured to receive high-definition video data and transmit the high-definition video data to the receiving side chip after performing first color space conversion, low compression, parallel-serial coding on the high-definition video data sequentially. The receiving side chip is configured to receive the high-definition video data transmitted from the transmitting side chip and output the high-definition video data to a display device for display after performing serial-parallel decoding, low decompression, and second color space conversion on the received high-definition video data. With the above signal extension system, a transmission distance of the high-definition video data is extended.