The invention discloses an electronic countermeasure-oriented digital radio frequency front end and a radio frequency signal frequency detection method. The digital radio frequency front end comprisesa radio frequency receiving front end module, a radio frequency detection module, a digital receiver module, a digital transmitter module and a radio frequency transmitting front end module. The radio frequency receiving front-end module receives the space signal, performs preliminary filtering and amplification processing, and sends the space signal to the radio frequency detection module to judge whether a radar signal exists or not and obtain a digital radio frequency signal with a specific carrier frequency; said signal is transmitted to the digital receiver module to form a low frequencybaseband signal, and the low frequency baseband signal is sent to the digital transmitter module to generate an interference baseband signal with the same frequency, and the interference baseband signal is converted into an analog radio frequency signal which is transmitted to the radio frequency transmitting front-end module to be subjected to noise reduction and amplification and then is transmitted out. According to the invention, wide-bandwidth radar signals with multiple frequencies can be received, interference radio-frequency signals are accurately generated to realize an electronic countermeasure effect, the defects of low frequency and narrow bandwidth of traditional high-frequency signal frequency detection equipment are overcome, and the requirements of a modern electronic countermeasure platform are met.