For high-precision measurement of target polarization information, a high-precision spectro-polarimetric analyzer is developed, which combines existing high-precision standard detectors technology with polarization detecting theory. By continuous and equiangular rotation of the polarizer, Fourier progression algorithm is used to calculate degree of polarization and it can greatly reduce uncertainty caused by angular error of polarizer. Optimum design of main optical path and fine linear standard trap detector with large dynamic range ensures the measurement precision. A set of alternate narrow-band filters are used to achieve degree of polarization measurement of continuous spectrum. The test results show that the degree of polarization is from 0.1 to 0.99, and the measurement uncertainty of spectro-polarimetric analyzer is below 0.15%.