Abstract: A self-propelled cleaning device includes a chassis with a protrusion, such that a side brush mechanism is proximate to the external periphery of the contour of the chassis, and an elastic element installed between a driving wheel set and the chassis for providing buffer and shock absorption. An interval is formed between the front edge of the chassis and a dust inlet for guiding dust into a dust collecting case in a chassis containing groove, and the containing groove has a first spacer apart from a control unit and a second spacer separating a carrying space from a negative pressure device. The second spacer has a passage interconnecting the containing groove and the carrying space, and the dust collecting case has separated first and second sides.