A K-band microwave interferometer for detecting shock wave induced displacement is demonstrated. Target displacement by laser induced shock wave has been widely used for material characterization and adhesive bond testing. In optical interferometers, the surface displacement related to the interface stress is measured by counting the number of fringes which requires additional postprocessing steps. The longer wavelength of a microwave interferometer allows direct reading of the surface displacement. Detection of the shock wave induced displacement on a plastic target is measured using a microwave interferometer then the measured results are compared to the standard optical interferometer results. The advantage of using a microwave-based system is discussed and possible application is demonstrated.