A design method of refraction⁃reflection hybrid lens was proposed. The lens consisted of five freeform surfaces. The rays with large angles were refracted by two freeform surfaces, and the rays with other angles were reflected to increase the spot size. The energy grid mapping relationship between the light source and the target surface was firstly established, and the freeform surface was constructed based on Snell's law. The simulation results showed that the illuminance distribution of the target plane could meet the design requirements when there was the point light source. However, the uniformity became poor when the extended light source was included. The uniformity was improved by modifying the illuminance distribution of the target surface. The actual test results showed that the uniformity of backlight unit achieved 86.8%, which could meet the design requirements. The designed and optimized refraction⁃reflection hybrid lens could effectively reduce the optical distance and satisfy the requirements for practical application.