Abstract: Micro Deformation Monitoring Radar can monitor the observation area all-day, all-weather, non-contact, large-area, sub-millimeter precision deformation displacement monitoring, and its monitoring accuracy analysis is a key scientific issue for deformation analysis and accurate early warning. In this paper, a portable omni-directional Micro Deformation Monitoring Radar system is used to conduct accuracy research and test analysis. First, the one-dimensional and two-dimensional signal models of the Portable Omni-directional Micro Deformation Monitoring Radar are derived, and the factors affecting the monitoring accuracy of the Micro Deformation Monitoring Radar system are analyzed. Secondly, a one-dimensional deformation monitoring experiment is designed, using a strong reflector, such as a corner reflector, as the observation target, which is connected to the optical prism. The results of the radar monitoring and total station monitoring are compared to analyze the accuracy of one-dimensional deformation. Finally, the observation scene is simulated with a distributed corner reflector to analyze the two-dimensional deformation monitoring accuracy of the Micro Deformation Monitoring Radar. The experimental results of one-dimensional and two-dimensional deformation monitoring show that the monitoring results are consistent with the actual displacement, the designed reference angle inverse measurement average is within 0.1mm, and the system deformation monitoring accuracy can reach sub-millimeter level, which can achieve high-precision micro-deformation monitoring application.