Provided is a mobile apparatus obstacle detection system (100), a mobile apparatus (10) carrying the obstacle detection system (100), and a ground-sweeping robot. The obstacle detection system (100) comprises: a structured light projection module (102) configured to project structured light onto the path of advance of the mobile apparatus (10), the structured light comprising at least one lateral detection line in the horizontal direction and at least one longitudinal detection line in the vertical direction; a camera module (103) configured to capture an image of the structured light (105); and an image processing module (104) configured to calculate, according to the image of the structured light (105), the distances and positions of obstacles (106, 107, 108) on the path of advance.