Abstract: The cosmic ray muon imaging method, as a high-resolution, high-precision passive detection technology, is sensitive to the density of matter and does not require the in-situ measurement, and it is expected to be an effective approach for the structure and the composition of the shallow surface and the internal matter of Mars and asteroids. In view of the limitation of the gas detectors and the liquid detectors, a multi-channel readout plastic scintillator array detector is designed for the acquisition of signals from multiple detectors. A detector system is set up to conduct the natural background muon detection experiments under laboratory conditions. and the zenith angle and the azimuth angle of the detected muon data are analyzed. It is shown that the angle distributions of the muon track are similar to those of the theoretical prediction, thus the applicability of the designed detector system is verified.