This paper is the use of optical heterodyne interferometry to measure the change in the refractive index of total reflection measured analyte. For homogeneous transparent material, the refractive index is uniformly distributed, when tested interface satisfies the total reflection condition, i.e., total reflection occurs, this beam will be totally reflected by the interface between the introduction of the vertically polarized light and horizontally polarized light a phase difference caused by the total reflection effect, this phase difference with the refractive index and the angle of incidence of the relevant interface. The results will explore the changes caused by the total reflection phase, and by this instrument will measure the phase change.