In order to reduce the reliability of data transmission through long cable in aerospace test, a high reliability transmission system based on FPGA is designed. Transmission system hardware adopts Chengdu vibration core domestic chips GM8223 and GM8224, with the use of drivers and equalizers to increase and enhance the driving ability of the circuit; Preweight design is added to enhance the high frequency component of the signal and compensate attenuation. The software of the transmission system explains the high reliability transmission in terms of the initialization of the sender, LVDS transceiver logic flow, and CRC+ 8B / 10B dual coding. Initialization can ensure that the sender sends a valid number; CRC+ 8B / 10B dual encoding reduces bit error rate by sacrificing bandwidth. It has been verified by practice that zero bit error rate transmission can be achieved on the 240Mbit/s coaxial cable with the length of 120m.