Digital receiver signal detection method

The invention discloses a digital receiver signal detection method. The digital receiver signal detection method includes the following steps: receiving optical fiber packaged data packaged by a digital receiver through an optical fiber receiving and sending module firstly; then, demodulating the packaged data to acquire echo data through an optical fiber demodulation module; separating multi-channel digital receiver data through a common-frequency clock according to channels; solving independent echo data of each channel; carrying out IQ separation on the echo data; sending the solved IQ data into a digital to analog (D/A) converter on one hand to carry out D/A conversion by using the common-frequency clock, and outputting the IQ data to an oscilloscope directly for observation; and on the other hand, storing the solved IQ data at the same time, and carrying out time-domain and frequency-domain analysis on the IQ data. The digital receiver signal detection method can solve the problem that closed loop real-t