A high-transmittance broadband millimeter wave metasurface structure with gradient phase is presented, and the metasurface structure works in the 55-75 GHz frequency band. This proposed structure comprises two dielectric layers and three metal layers. The intermediate metal layer is notched rectangular ring which can adjust the phase in the range of 0-2π by adjusting the geometry. The function of the notched rectangular ring is to achieve polarization conversion. The transmission phase difference of construction units with different notched rectangular rings basically remains unchanged in working frequency band, thereby ensuring the broadband property. The grid layer ensures the high transmission performance of the metasurface structure. The proposed metasurface structure is successfully applied to the metasurface designs of a planar lens and orbital angular momentum beam.