The technique of polarization has been applied to measure the polarization properties of atmospheric scattering radiation. The state of polarization of atmospheric scattering has the mutable character in time and space. It requires that the instrument has the capacity of obtaining the measurement data in real-time. A new type of polarimeter has been developed for this requirement. The radiation value of three polarized transmission optical axis is obtained at the same time using this mode of system, which can get polarized characteristic of target in real-time. The structure design of software and hardware is presented. A kind of signal sampling system is introduced. This system uses the USB sampling card as its core component. The instrument is calibrated using of integral sphere. The calibration data are analyzed. The results show that the system meets the requirement of atmospheric polarization detection.