Abstract: Mars is the next milestone in our exploration of solar system.Due to the very long distance between the Earth and Mars（the longest distance is about 400 million kilometers，and the light travel time is about 22 minutes），in order to maximize the efficient communication between the Mars rover and the Earth，the inter vehicle relay communication technology between the Mars rover and the Mars Orbiter is particularly important.Aiming at overcoming the difficulties of low signal-to-noise ratio，rapid change of signal parameters，high requirements for full autonomy and extremely strict weight and power constraints of inter device communication in large elliptical orbit，a UHF band relay communication technique was proposed，mainly including ultra-high sensitivity and high dynamic adaptive signal demodulation，high precise Doppler measurement，the CCSDS Proximity-1 multiple dimensional integration and the highly integration and RX/TX isolation engineering design of transceiver product，achieving the acquisition sensitivity better than -141dBm，demodulation sensitivity（1kbit/s）better than -134dBm，frequency dynamic range better than ±26kHz，Doppler measurement precision better than 10mHz，RX/TX isolation greater than 180dB，fully autonomous，high reliability and high throughput communication in the visible arc section and system/product extreme optimization.The relevant performance indexes are better than the "Electra" in the American series of Mars probes.After the actual onorbit tests of the “Zhurong” Mars rover，the “Tianwen-1” Mars orbiter and the ESA “Mars Express” orbiter，the test data met the expectations and made a key contribution to the success of China′s first Mars exploration.

Key words: Mars exploration, UHF band, relay communication technique, CCSDS proximity-1 protocol, Design of product engineering