Based on the principles of laser diode linear frequency modulation heterodyne interference and frequency division multiplexing, the multiplexing technique of the optical fiber displacement sensor is studied. A two-dimension-multiplexing optical fiber displacement sensor is designed and fabricated. The problem of the crosstalk of signals is studied. The experiment proves that the cross-term of the sensor is smaller than 0.02μm and the measurement accuracy of each channel is 0.05μm.