Glucose concentration measurement is crucial in various fields, including biology and medicine. This study proposes an orthogonal mirror to eliminate the 180° flipping of the polarization that generally occurs following single reflections from a metallic mirror to enhance the resolution of the polarimetry for measuring glucose concentration. The relationship between the solution concentration and the phase difference of reference light and measurement light is established. Furthermore, the effect of multiple polarization rotation based on the orthogonal mirror is explored. Multiple polarization rotation increases the glucose concentration measurement resolution without increasing the sample length. Taking glucose solution as an example, the experimental results of four rotations demonstrate that the concentration measurement resolution is 8×10^-6 g/mL in the range of 0-0.4690 g/mL with a maximum relative error of less than 0.54%. The proposed approach can be used for online and real-time glucose concentration detection for research on glucose abnormalities in the pathogenesis of autism spectrum disorders.