The invention discloses a realization method of selective diversity combining, and relates to the communication filed and signal receiving and processing technologies in the communication countermeasure field. According to the invention, algorithm modules such as a signal to noise ratio analysis module, a decision criterion performance analysis module and a phase analysis module are provided. Based on independence of dual-path horizontal space antenna receiving signals, and according to the performance of signals demodulated and output by a demodulator after each path of antenna receiving signals is input into the demodulator, the branch output signals high in signal to noise ratio are selected for judgment, so that the signal to noise ratio of the output signals is improved and doubled. According to the invention, the unusable time and signal quality reduction caused by fading are substantially reduced for channels having a serious fading phenomenon, and the receiving performance is effectively improved.