Multi-angle polarimetric radiometer is the instrument that obtains multi-angle, spectrum, and polarization information of atmosphere by scan mode. According to the theory of measuring multi-angle polarization information of atmosphere, the multiplex data collection system in the multi-angle polarimetric radiometer was designed. And this system was tested by experiments. The results indicate that the multiplex data collection system in the multi-angle polarimetric radiometer can meet the requirements of designing.