Abstract: In order to solve the technical problems of large high-frequency ground-based radar radome such as large steering error, low electromagnetic wave transmission rate, low structural security and environmental worthiness, a new block metal frames radome based on flexible skin is proposed. The design method of the radome is elaborated respectively from aspects such as design of block size, simulation of induced current ratio, design of electromagnetic window, structure simulation and optimization, the technique of pretension control and the sealing design. An X-band block metal frames radome with the diameter of 28.5 m is designed and manufactured, which proves the effectiveness of the proposed method. The method can also be applied to the study and development of various large high-frequency ground-based radar radome.