The invention discloses a full duplex system with a high dynamic receiver and a use method thereof. The system comprises a transmitting antenna module, a receiving antenna module, a first shunt, a waveform detection module, a second shunt, an adjustable gain device, a receiving channel module, a first ADC, a second ADC and an envelope restoration module. The output signal of the waveform detection module is an envelope inverse ratio function of an input signal. Gain adjustment can be carried out through an adjustable gain module, compared with the input signal g(t), the output signal j(t) obtained through zooming processing controlled by a gain control signal h(t) has the advantage of remarkably reducing the peak-to-average power ratio, and therefore compared with g(t), the requirement of j(t) for the dynamic range of a receiving channel is remarkably reduced. In ideal conditions, the output signal x(n) of the envelope restoration module is the discretization signal of g(t), it is equivalent to the fact that the receiver completely receives a high dynamic signal, and on the contrary, it is equivalent to the fact that the dynamic state of the receiver is greatly improved.