When different images are presented to two eyes, they compete for perceptual dominance, such that a region of one image is visible while corresponding region of the other is suppressed. This visual phenomenon is called binocular rivalry. Binocular rivalry may be introduced in stereoscopic images of natural scene, leading to strong visual discomfort and visual fatigue. When binocular differences exceed a threshold, binocular rivalry occurs. Binocular difference threshold of corresponding regions increases with background complexity of the region. Based on these features of human visual system, we proposed a detection model of binocular rivalry for natural image pairs. A binocular rivalry database was established and used to evaluate our detection model with the database. Experimental results demonstrate that the proposed model can achieve higher hit rate and lower false alarm rate compared with existing method.