Abstract: In order to make the displacement measuring system achieve the large-range and high-resolution,theoretical analysis and experimental verification were conducted with the multiplexed fiber interferometer.Two fiber Michelson interferometers sharing common-interferometric-optical path were configured by employing fiber Bragg gratings as in-fiber reflective mirrors.One of the interferometer was used to stabilize the measurement system with a feedback loop compensating the influence induced by the environmental disturbance so that the measurement system was kept stable enough for on-line measurement,while the other one was for performing the measurement task.Two different wavelengths are working simultaneously in the measurement interferometer.The measurement range determined by the synthetic-wavelength interferometric signal of the two wavelengths was expanded to be larger than 1mm,while the measurement resolution determined by one of the single-wavelength interferometric signals was maintained less than 1nm.The displacement measurement system achieved the large-range and high-resolution purpose based on multiplexed fiber interferometry.