We propose and realize a simple technique to measure the tiny spin Hall effect of light from the ratio of the minimum and the maximum intensities along two cross-polarization directions, without the requirement of a position-sensitive detector in the conventional weak measurement. Furthermore, the weak intensity ratio is dramatically amplified by purposely choosing the intensity along the direction close to that of the minimum instead of the maximum along the perpendicular polarization direction, which is verified by the experimental results. In principle, this method also can be modified for measurement of the high extinction ratio of a polarizer.