The invention discloses a self-adaptation four-port cancellation network structure and a self-adaptation cancellation method. The structure comprises an amplitude-phase cancellation network and a self-adaptation adjusting structure, wherein the amplitude-phase cancellation network comprises a coupler, an adjustable gain amplifier, an analog phase shifter, a power amplifier, a matched load and a attenuator, the aim that the transmitting chain is coupled with part of energy is achieved, amplitude phase adjustment is performed on a coupling signal, then, the amplitude of a received link coupler and the amplitude of a received same-frequency interference signal are approximately equal, the phase of the received link coupler and the phase of the received same-frequency interference signal are approximately opposite, finally, the amplitude of the received same-frequency interference signal is restrained to be on a lower level, and therefore the received channel carrier-to-noise ratio is improved. The self-adaptation adjusting structure comprises a coupler, a detector, a comparator matched load and a gain adjustable amplifier, the amplitude of the received same-frequency interference signal set on a parallel comparator public reference end is restrained to be the target level detection voltage, and a loop self-adaptation adjusting structure can automatically adjust the adjustable gain amplifier and the analog phase shifter in the amplitude phase cancellation network.