Abstract: A novel ellipse cylindrical dielectric lens antenna array is designed in this paper. In order to improve antenna radiation properties, considering high voltage breakdown based on high power application, this paper proposes filling transformer oil in a nylon radome structure of an elliptical cross-section and rectangular combination, then sealing a knife-shape antenna array in the structure, and eventually forming a dielectric lens antenna array. The geometric focusing capability of ellipse and shrinkage of wavelength helps to enhance the main lobe gain and the electric size of the antenna array. Compared with the traditional antenna array, it shows that the peak-to-peak voltage value along the antenna axis in the far field pattern increases by 41% via changing the array distance, while the far field beam width decreases obviously, and the gain enhancement is 4.96 dB. Furthermore, the front to back ratio gets better, the power capacity is up to 9.63 GW, 338 times greater than that of the former structure.