Abstract: In order to improve the luminance and brightness uniformity of mobile phone side backlighting light guide plates (LGP), a wedge-shaped LGP with the upper surface of 41mm26mm was simulated. The printing scattered dots on bottom surface, the wedge angle of LGP underside and hemispherical convex hull arrangement on the surface were researched. The results showed that the brightness uniformity of upper surface was poor and the percentage of output luminous flux was less than 26% when the LGP bottom was printed with scattered dots, the brightness uniformity of upper surface was improved and the percentage of output luminous flux is increased by 10% when the hemispherical convex hulls were arranged on the LGP bottom. The lighting effect of LGP with 81 wedge angle was better than 85.