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.