Abstract: In order to obtain higher measurement resolution,an analogical differential-phase low homological optical reflecting system was developed with a differential amplifier combined with a high magnification microscope objective lens based on a low homological light source and a Michelson interferometer.High signal-to-noise ratio and high sensitivity can be obtained by means of the balanced detecting structure.The high time-frequency width product can be acquired by using the differential amplifier with frequency width of 100MHz.Thus a higher sensitivity can be achieved for measuring the surface morphology and moving rate.The result indicates that the local measurement by use of a super luminiferous diode(SLD) with narrow frequency width and a microscope objective with large number aperture has the same effect on local location.