The sky polarization pattern is an important feature of the atmospheric effect of remote sensing observation. It describes the distribution of polarization information in all sky. The atmospheric effect on polarization observation is immense, and analysis of the method of the atmosphere acting on polarized light is the basis, it can provide a new idea for reducing the impact of atmospheric effect on polarization images. Because different regions and different observation situations correspond to different sky polarization patterns, it is a prerequisite to develop instrument to research the polarization pattern of the sky. The emphasis of this paper was on the design of an all-sky polarization observation system and validating it through precision measurement. It introduced main parts of the instrument firstly, including mechanical structure, optical design and circuit control, then the instrument control accuracy was described by analyzing control strategy and control precision of the instrument. At last, by contrast experiments, the results prove the reliability of polarization observation instrument.