Abstract: Multifunctional radio frequency (RF) integrated technology is in the process of rapid development, in order to fully meet the multifunctional integrated operational requirements in the new era, it is necessary to optimize the hardware architecture of multi-function RF integrated technology, expand related functions and improve the integration density, and promote the rapid development of the technology. The architecture of a multifunctional RF integrated system is firstly proposed in this article，and the key technologies of multifunctional RF systems such as ultra wideband array technology, simultaneous transceiver technology, and integrated waveform technology is summarized. Then, the key technologies of the RF integrated system were studied, and the key points of ultra wideband array technology such as low profile broadband wide-angle scanning antenna array, multifunctional integrated chip, and high-density chip layout were analyzed. The characteristics of the methods for improving isolation in time domain, radio frequency domain and digital domain are summarized; The integrated waveform technologies such as time-division complex, frequency-division complex, space-division complex and signal sharing are compared and analyzed. Finally, the development prospect of multi-function RF integrated system is proposed.