Abstract: The stealth performance of warships is directly affected by its mast;therefore, the analysis and evaluation of the stealth performance of the ship's mast in the preliminary design stage is the main research purpose of this paper.By taking a typical enclosed ship mast as the research model, the influences of several important parameters on the stealth performance are analyzed, with the major scattering characteristic of the mast being investigated.It is seen that most of RCS peak points are caused by the specular reflection, and the optimal adjustment of mast configuration is presented.When the ship is rolling, the dihedral angle effect caused by the affiliated platform and main structure would intensify.This paper provides a reference for the stealth performance evaluation and improvement of mast configuration in the preliminary design stage.