The precision positioning device becomes significant requirement in scientific instruments used for the applications of nanotechnology for a few decades. To achieve the high resolution positioning, the sensing methods of displacement sensor become more important in positioning device. In this paper, a novel method is presented for measuring both in-plane/out-plane displacements with the single heterodyne grating interferometry (HGI). We demonstrated the 1D, 2D, and 3D measurement results respectively and the smallest displacement can be detected was better than 6 pm. Furthermore, the nanometer resolution can be ensured within 20 µm displacement. Hence, the in-plane/out-plane measurements with single apparatus can be realized by our method and might be a displacement sensor using in the motorized stage with suitable opto-mechanics structure minimization.