Polarization converter is widely used in many engineering fields such as wireless communication,radar detection and so on,aiming at the current application requirements of ultra-wideband,multi-function and high-efficiency,a dual-polarized,multi-band reflective polarization converter is proposed.Based on the metasurface,the structure is composed of three parts:metallic patch arranged periodically in top layer,dielectric layer and metallic plate in bottom layer.The research shows that for the incident linear polarization wave,the structure can realize cross-polarization conversion in the three bands of 6.2—6.7 GHz,17.7—19.2 GHz,20.88—21.14 GHz with a polarization conversion ratio (PCR) of over 90.It can realize linear-circular polarization conversion in the two bands of 7.12—16.68 GHz, 19.47—20.67 GHz with a axial ratio (AR) of below 3 dB.This design has the characteristics of simple structure,convenient manufacture and low-energy consumption,it has certain theoretical and practical value in electromagnetic wave polarization controlling and microwave device designing and so on.