A self-reconfigurable returnable mixer includes a self-reconfigurable transconductance stage. The input RF voltage signal is converted into RF current through the self-reconfigurable transconductance stage. The RF current is converted into an IF signal through down-conversion and low-pass filtering. The IF signal is fed back to the reconfigurable transconductance stage; the self-reconfigurable transconductance stage presents an open-loop structure to the input RF voltage signal, and the self-reconfigurable transconductance stage presents the topology structure of the negative feedback amplifier to the fed-back IF signal. The self-reconfigurable transconductance stage circuit achieves a high-linearity IF gain while providing a high bandwidth for the RF signal, effectively alleviating the contradiction between the conversion gain and the IF linearity in the conventional returnable structure.