In order to clean unknown outdoor environments, we devised a novel outdoor cleaning robot using mainly on-board vision-based auto-navigation in this paper. The track-driven and cleaning mechanisms of the robot are designed for cleaning tasks in outdoor rough terrain. A single image sensing module is exploited for clean-region detection and three ultrasonic ranging modules are used for obstacle avoidance. The cleaning task is performed autonomously after the boustrophedon path planning is completed in the grid-cell map. The map is obtained from transforming the two-dimensional images captured by the image sensor. The robot also self-localizes based on the deduced boundary lines at the end of each cleaning stage to continue its unfinished cleaning work. The experimental results prove that our outdoor cleaning robot performs well in general outdoor environments.