Background <p>Three-dimensional digital image correlation (3D-DIC) has been widely applied for deformation measurement. However, the two-dimensional (2D) image coordinates based shape functions can not accurately describe the deformation characteristics since all tested objects are three-dimensional (3D).</p> Objective <p>The present work aims to address the issue of imperfect matching (either under-matching or over-matching) in the application of two-dimensional first- or second-order shape functions within the three-dimensional digital image correlation method.</p> Methods <p>This paper proposed a novel 3D coordinates correlation (3DCC) methodology that synergistically integrates fringe projection and speckle imaging techniques to advance deformation analysis. The proposed method utilizes 3D coordinates shape functions instead of 2D image coordinates ones, thereby aligning more closely with the principles of Strain-Displacement Relations in continuum mechanics, and significantly improving the accuracy of deformation measurement.</p> Results <p>Simulation experiments were conducted to assess its convergence and accuracy with Gaussian image noise. Comparative analyses were performed between the commercial 3D-DIC software and the proposed 3DCC method using two real experiments: a pure translation of a wedge-shaped mechanical element and a four-point bending of an acrylic beam. A greater than 50% enhancement in accuracy has been achieved.</p> Conclusions <p>The experimental results demonstrate the accuracy of the proposed 3DCC method in measuring displacement and strain, particularly for objects with complex geometries or those undergoing non-trivial deformations.</p>