The invention relates to the field of photovoltaic cell panel cleaning, and particularly relates to a photovoltaic cell panel cleaning device as well as a slope-crossing control method, a control system and an array thereof. The control method comprises the following steps: determining the running manner of the cleaning device on a photovoltaic cell panel structure; enabling the photovoltaic cellpanel structure to be step-shaped; when the running manner is slope-crossing, determining the intersection point of the perpendicular bisector of the bottom surface of the cleaning device and the photovoltaic cell panel structure; when the intersection point is located on an upper photovoltaic cell panel or a lower photovoltaic cell panel, determining a first included angle between the cleaning device and the upper photovoltaic cell panel or the lower photovoltaic cell panel, determining a width between travelling wheels of the cleaning device, and calculating the stretching distance of a brush of the cleaning device according to the first included angle and the width; and when the intersection point is located on a slope surface, determining a second inclined angle between the cleaning device and the slope surface, determining the width between the travelling wheels of the cleaning device, and calculating the stretching distance H of the brush of the cleaning device according to the second included angle and the width. According to the technology, effective cleaning for the cell panels in the case of slope-crossing can be realized.