The whole Stokes measurement instrument based on aperture segmentation can obtain all polarization information of the target, but the polarization detector system has an effect on the measurement results. So it is necessary to analyze the measurement error of the Stokes vector [S0,S1,S2,S3]. First, the theory of Stokes vector was researched; next, the working and measuring principle of the full Stokes measuring instrument were introduced; then, the error sources were analyzed; last, the influences of the error sources were simulated. The final simulation results show that, the relative error of polarization and elliptical angle are 1.16% and 4.55% when the phase retardation is ±5°, the relative error of azimuth angle is 7.68% when the fast axis direction of the wave plate is ±2° with respect to the x axis, and the relative error of polarization degree, elliptical angle and azimuth angle is about 1% when the signal-to-noise ratio of CCD detector is 40 dB. The analytical results provide reference for the selection of the component parameters of the experimental device, and support for the full Stokes measuring instrument based on aperture division.