Abstract: In order to solve the Radio-Frequency Interference (RFI) problem faced by spaceborne radiometer, a joint detection method of RFI for spaceborne microwave radiometer is proposed, which combines polarization detection and statistical domain detection in each subband by means of digital channelization. Firstly, Stokes parameter and polarization detection algorithm are introduced, and then the polarization detection algorithm and kurtosis detection algorithm are simulated and analyzed. Combined with the digital channelized receiving mode, the polarization detection algorithm and kurtosis detection algorithm are jointly designed to make up the detection blind spot of the kurtosis detection algorithm when the duty cycle is 50%, optimize the signal-to-noise ratio requirements of the polarization detection algorithm, achieve a fast detection method with high resolution and give the system simulation performance. The software implementation complexity is low, the resources are small and easy to reuse. It is suitable for the engineering realization of RFI detection of spaceborne microwave radiometer.