Aiming at the characteristics of long propagation distance and large Doppler frequency shift caused by the high-speed movement of low-Earth orbit satellites around the Earth, the impact of Doppler frequency shift on satellite to ground synchronization and communication quality is analyzed. Doppler frequency shift calculation and pre compensation techniques are implemented based on ephemeris information and network planning and other situation prediction methods to coarse compensate for satellite to ground Doppler frequency shift, and the characteristics of direct spread spectrum sequences used in physical layer waveforms are combined, Complete frequency shift tracking and correction through delay locking, ensuring high-quality and reliable connection of satellite links, and ensuring efficient, reliable, and safe operation of the satellite Internet of Things.