A new type of radially polarized grating is designed to solve the problems of nonlinear measurement of Faraday rotation existing in the power optical sensing. The distribution of the grating vector is in accordance with the special method, so that the polarization distribution of the polarized light can be transformed into the dis-tribution of light intensity, which rotates synchronously with polarization plane. The theory of polarization detec-tion is analyzed by using Jones matrix, and the parameters of the grating are simulated by rigorous coupled wave theory. Finally, the grating is fabricated and tested. The results show that the TM transmittance of the grating is greater than 80%, the extinction ratio is greater than 100, and the detection of the polarization state can be re-alized. It has the advantages of large linear measurement range and measurement results independent on the absolute intensity, so that it will be a new detection technology of polarization based on the image method.