A communication method for phase separation differential chaos shift keying (DCSK) based on a second order hybrid system (SOHS) is provided. The method includes the following steps. At Step 1: communication system parameters are set. At Step 2: binary information to be transmitted are prepared. At Step 3: the chaotic signal u(t) is generated. At Step 4: the chaotic signal is prepared to be transmitted. At Step 5: a received signal is demodulated. At Step 6: a chaotic matched filtering operation is performed on the demodulated reference signal and the demodulated information bearing signal. At Step 7: optimal signal to noise ratio (SNR) points are extracted in a sampling way. At Step 8: polarity of each symbol is determined to obtain a recovered signal.