As the fields in which electromagnetic interference shielding composites are applied become more diverse, polymer materials with excellent mechanical properties, high EMI shielding effect and capable of long-term operation are highly desired. Herein, we prepare flexible and reprocessable EMI shielding composites via the incorporating Ti3C2Tx MXene into crosslinked polyurethane (PU). The MXene/PU composites exhibit excellent reprocessing abilities such as tensile strength recovery, EMI shielding effect, and high electrical conductivity after heat treatment. In addition, the oxidation stability of MXene in the composite is evaluated by monitoring the UV-vis absorption profile and the morphology of TEM images as a function of storage time under an air atmosphere. Further, high flame-retardant properties were achieved due to the high char residue.