According to the visual mechanism of the human, the implementing method and the visual model of the visual saliency for the computer are introduced from the direction, brightness and color. This visual model can be used for the target detection by combining with the artificial and natural methods. The background images of the vehicles in the database are observed. The experiment shows that in 75% of the images, the computer model detects the target faster than the human, and this model is more suitable for detecting the obvious target.