A technique with carrier modulation for three-dimensional displacement measurement by using electronic speckle pattern interferometry (ESPI) is presented. Firstly, a new block prism, named large-shearing block prism, is designed. A large-shearing electronic speckle pattern interferometer can be constituted when large-shearing block prism is used. Secondly, the test object and reference object are illuminated separately by three lasers which are fixed on horizontal and perpendicular position. A new three-dimensional (3D) ESPI system is constructed by three lasers, a large-shearing block prism and a CCD camera as well as a reference object. The carrier fringes in three interference fields can be introduced by rotating the reference object with a small angle. Interference speckle patterns before and after deformation, and interference speckle patterns after rotation of reference surface are collected when three lasers are used respectively. After the images are subtracted, three carrier fringe patterns and three modulated carrier fringe patterns under different illumination are obtained. Finally, three phase maps can be demodulated by using Fourier transform. Further phase calculation is needed to separate three displacement components. A typical three-point-bending-beam experiment is completed by the 3D system presented. Experimental results are offered, which show that three displacement components can be determined effectively. The 3D system has simple optical setup and has an easy way to operate, therefore it provides a new approach to three-dimensional deformation measurement.