Due to the tiny shift in order of optical wavelength for Goos-Hanchen (GH) shift, it is very difficult to measure it directly. A novel approach to directly observe the small optical beam shift was proposed based on the liquid crystal light valve (LCLV) and the light beam profiler (LBP). Polarization of the beam through the LCLV is investigated. It is shown that polarization of the beam changes when the applied voltage changes. The LCLV is utilized to modulate the polarization state of the beam and LBP is used to register the barrycenter of the beam. The difference between the TM and TE polarized longitudinal Goos-Hanchen shift at the condition of total internal reflection on a prism-air interface was detected. This method doesn’t need complex external processing circuit, and the experimental result shows good agreement with theoretical calculation. The method is advantageous to measure simultaneously the two-dimensional laser beam shift.