A shearing interferometer which comprises a beam displacer, polarizer, and CCD camera is prosed in this paper. The shearing plate of this interferometer is the bam displacer which splits a laser beam passing through it into two components that are laterally separated, parallel, and orthogonally polarized. Thus, as these two components propagate through the polarizer and then to the CCD camera, s hearing interference pattern is generate and recorded. The optical setup of this interferometer is described, the results show that this interferometer can be adopted for inspecting the wavefront of a laser beam, the strains of a specimen grating, and the strains of a diffusion object. Three experiments were carried out in this paper. The first was to determine the radius of curvature of a spherical wavefront, the second was to measure the strain of a circle diaphragm bonded with a grating, and the third one was to detect the strain of a square diaphragm with diffusion surface. Experimental results confirm the validity and applicability of this interferometer.