This paper concentrates on the effect of out-of-plane translation on the 2D-DIC and its elimination. The strain errors caused by out-of-plane translation are presented in the form of equations. In this paper, a novel experimental technique is suggested to eliminate the effect of out-of-plane translation in 2D-DIC. A planar laser beam is projected on the surface of the specimen to form a light strip on its surface. The position of the light strip will be shifted if the specimen is translated along the optical axis of the camera. The distance of translation can be calculated by comparing the location of the laser strip before and after translation. Verification experiments were performed to validate the effectiveness of the proposed method. Then the method is combined with the theoretical model to predict and eliminate the pseudo strains caused by out-of-plane translation. Results confirm that this method can predict the strain errors caused by out-of-plane translation to a precision of within 100με.