Disclosed are a system and a method for determining coordinates of a three-dimensional measurer probe using a beam phase interference method. Two optical fibers are mounted inside the probe, and detecting means obtains an interference pattern generated by beam emitted from a point beam source mounted at ends of the optical fibers. After that, wave front of the interference pattern is measured and a location of the point beam source is determined through a nonlinear optimization from the wave front, and thereby the coordinates of the three-dimensional measurer probe are set. Because the two optical fibers of the inside of the probe to be measured are located in close vicinity to the three-dimensional object, the present measuring system and method can reduce a measurement error, make a structure of the system simple, and thereby reduce a manufacturing cost.