Abstract: Lunar Antarctic is hot spot area of Lunar Exploration in the future and the communication is limited in south pole region. The Lunar relay communication needs to be designed to fulfill the science exploration mission. The requirements, characteristics and constraints of the relay communication mission of the lunar south are analyzed and the options for the communication orbit are put forward, including the elliptical orbit around the lunar and the translational point orbit. The advantages and disadvantages of the optional orbits are analyzed, The dual-satellite scheme is further proposed. This scheme can effectively improve the continuous coverage of the lunar south pole communication. The simulation results show that the two satellites can realize the visible complementarity of the lunar south pole, and reach real-time coverage of the lunar surface and the aircraft near the moon. It will provide reference for the implementation of the fourth phase lunar pole south exploration in the future.