ESPI/DSPI has real time subtraction function and has been used to measure fast deformation. But usually, ESPI/DSPI can not simultaneously acquire two frames which is needed for recording two displacement components (U, V) of in-plane fast deformation. In our experimental setup, the specimen is illuminated by 4 beams symmetrical to normal z. Two beams lie on x-z (y-z) plane with y (x) polarization. By using of a Wollaston prism, two speckle patterns are shifted without overlap. Only one CCD camera is adequate to capture these two patterns as one frame at the same time. An image processing system is used to get fringes patterns as U an V contours real-timely. A strip specimen has been studied by this method.