Abstract: The use of 3D printing processes can greatly improve the flexibility of the design of Luneburg lens antenna, and simplify the preparation process. This paper focuses on the key technologies for the design of isotropic Luneburg lens (LL) antennas, namely the polarization insensitivity and wide incidence angle characteristics of the unit cells. Secondly, the basic theory and design idea of LL antenna based on 3D printing technology are summarized, especially emphasizing the overall compromise between antenna performances and printing process. Finally, a LL antenna working in the X-band was designed and printed. The results of the test show that the antenna has good isotropy in the range of 8 GHz to 10 GHz. At 8 GHz, 9 GHz and 10 GHz, the measured gains of the main beam are 18.32 dB, 19.08 dB and 18.87 dB, respectively, and the corresponding aperture efficiency is 43.01%, 51.24% and 48.82%, respectively. Overall, the designed LL achieves isotropy while maintaining structural strength.