China has made a remarkable leap forward in the realm of satellite-ground high-speed communication technology. The Aerospace Information Research Institute, in partnership with Beijing Rongwei Technology Co., Ltd., has triumphantly carried out a satellite-ground microwave high-speed communication experiment. Leveraging advanced high-order modulation and demodulation techniques, the experiment substantially boosted the data transmission rate between satellites and the ground. It achieved an impressive 6.0 gigabits per second in the X-band frequency range and an even more remarkable 20 gigabits per second in the Ka-band, thereby setting new benchmarks. To tackle the technical hurdle of maintaining high-quality data transmission at such elevated speeds, the collaborative team engineered a 'signal purification' technology and established a high-performance ground receiving system. The outcomes of the experiment revealed that the novel technology significantly enhanced data transmission efficiency across various satellite frequency bands, featuring stable signals, minimal bit error rates, and exceptional communication quality. This experimental triumph heralds a new milestone for China in attaining high data transmission rates in both the X-band and Ka-band for satellite-ground communications. The high-order modulation and demodulation technology is now primed for implementation in real-world satellite data reception tasks, playing a pivotal role in overcoming bandwidth constraints in satellite-ground transmission and boosting the efficiency of satellite applications.