Conventionally,　the　polarization　of　a　synchrotron　soft　X-ray　beam　is　measured　through　a　polarimeter　based　on　multilayer　optical　elements.　The　major　drawback　of　the　traditional　approach　is　the　difficulty　in　comparing　different　configurations　due　to　the　misalignment　of　each　incident　angle.　In　this　paper,　a　new　analytical　model,　based　on　the　variation　of　reflectivity　for　different　incident　angles,　is　established　to　facilitate　the　extraction　of　important　polarization-related　information,　i.e.　angular　distribution　of　polarization　components,　a　tiny　change　of　the　direction　of　azimuth　rotation　axis　of　polarizer,　etc.