SummarySatellite‐ground‐link high‐rate high‐efficiency data transmission technique is one of the key supports for the development of high‐resolution low‐earth‐orbit (LEO) earth observation satellite systems. Ka‐band, frequency ranging from 24.6 to 40 GHz, shares a wide available bandwidth, high frequency reuse rate, and strong ability of anti‐jamming. Satellite operators have utilized the Ka‐band for satellite‐earth data transmission, which requires higher traffic capacity, and even have planned to launch new satellites with Ka‐band capacity. In this paper, we propose and experimentally demonstrate a 5‐Gbps uncoded data rate (corresponding to the channel rate of 6 Gbps) of Ka‐band data‐transmission system with dual‐circular polarization and frequency reuse for satellite‐earth applications. The objective of the experiment is gathering experimental data to validate the performance of the proposed four channel systems, including bit error ratio (BER) and link budget. Our work could support future satellite communication applications and meet the imperative demands of high rate transmission to earth.