The present disclosure relates to a skywave large-scale MIMO communication method, model, and system. A skywave communication base station in a short waveband is constructed using a large-scale antenna array, wherein skywave large-scale MIMO communication is carried out between the skywave communication base station and a user terminal in a coverage area by ionospheric reflection. The skywave communication base station determines a spacing of the large-scale antenna array according to a maximum operating frequency, and communicates with the user terminal based on a TDD communication mode, wherein a skywave large-scale MIMO signal is transmitted based on an OFDM modulation mode or a power efficiency improvement modulation mode. The skywave communication base station selects a communication carrier frequency within a short waveband range according to a real-time ionospheric channel characteristic, and adaptively selects an OFDM modulation parameter and a signal frame structure.