Based on the low transmission delay and transmission loss advantage of the LEO satellite communication systems and high resisting rain loss ability in S-band satellite communications, a transmission scheme for LEO S-band satellite-ground links is proposed in this paper. Under the specific number of users and transmission rate conditions, uplink and downlink transmission scheme and link margin evaluation of the LEO S-band satellite-ground links has been studied, and based on which anti-interference measures for satellite-ground links is proposed accordingly.