The invention provides a low-frequency communication method based on a satellite-borne mechanical antenna, and belongs to the technical field of low-frequency communication. The method comprises the steps that the mechanical antenna is installed on a communication satellite, solar energy is adopted for power supply, and global low-frequency communication is achieved in a multi-satellite networkingmode. According to the method, the influence on the normal operation of a communication satellite is reduced by using a mechanical antenna with a smaller load, the advantage of high penetrating powerof low-frequency electromagnetic waves can be fully utilized, the defect of overlarge size power consumption of an existing ground low-frequency communication transmitting antenna is overcome, and comprehensive and multi-level low-frequency communication is realized.