The invention relates to a visitor flow rate and popularity index detection method based on area definition and a detection system thereof. A computer vision technology and SVM are used to detect heads and shoulders of pedestrians. A tone-saturability histogram is used to realize rapid detection and tracking of a single pedestrian in an area of interest. A pedestrian number of the area is calculated and stay time of the single pedestrian in a defined area is acquired. Through combining a number of people in unit time and an area of the area of interest, a popularity index in the area is calculated. By using the method of the invention, accuracy of pedestrian detection and tracking is increased, and the computer vision technology is used to calculate the popularity index based on the defined area. The method and the system possess an extensive business value.