This paper proposes an absolute phase unwrapping method for three-dimensional measurement that uses two cameras and one projector. On the left camera image, each pixel has one wrapped phase value, which corresponds to multiple projector candidates with different absolute phase values. We use the geometric relationship of the system to map projector candidates into the right camera candidates. By applying a series of candidate rejection criteria, a unique correspondence pair between two camera images can be determined. Then, the absolute phase is obtained by tracing the correspondence point back to the projector space. Experimental results demonstrate that the proposed absolute phase unwrapping algorithm can successfully work on both complex geometry and multiple isolated objects measurement.