Possible errors in baseline length and angle measurements are qualitatively and quantitatively analyzed to reduce errors in the dynamic monitoring of baseline measurements of the dual-antenna InSAR system that affect the baseline measurement accuracy. First， by establishing a systematic error model， the error source of the measurement system was identified. The error sensitivity was introduced to quantitatively estimate the error term and conduct sensitivity analysis of the error term for each degree of freedom， further generating quantitative synthesis results of the comprehensive error. A set of accuracy inversion error assignment cases was analyzed. The Monte Carlo method was used to verify the feasibility and robustness of the proposed method for accurate quantitative analysis allocation in a simulation closed-loop. The simulation analysis results show that when the accuracy of the position measurements is 300 μm （3σ）， and the accuracy of the triaxial angle measurements is 50'' （3σ）， the baseline length accuracy can reach 1 mm （1.6σ）， and the baseline angle accuracy is 2″ （1.6σ）. By using this method， the accuracy of baseline measurements can be obtained directly from the input of the measured environmental conditions. The inversion of the error assignments according to the sensitivity coefficient yields the optimal layout of the system. The results are valuable for effectively guiding scheme designs and analyzing the error distribution of the measurement system.