The present invention discloses a photovoltaic module cooling system based on an IoT (Internet of Things) technology. The cooling system comprises a horizontal table, and the upper portion of the horizontal table is provided with a photovoltaic solar panel array; and the photovoltaic solar panel array at least comprises a first column of photovoltaic solar panels, a second column of photovoltaic solar panels, a third column of photovoltaic solar panels and a fourth column of photovoltaic solar panels which are mutually distributed in parallel. The structure is simple, the photovoltaic solar energy module can start an active cooling mechanism at the extreme hot sun weather to perform immediate and effective cooling for the photovoltaic array so as to prevent the cell panel from being exposed to the sun and damaged; a cooling robot goes by a first straight rail, a first bending rail, a second straight rail, a second bending rail and a third straight rail in order; and moreover, a water pump is turned on during going by the first straight rail, the second straight rail and the third straight rail to allow the cooling robot to complete walk the whole water channel rail to achieve uniform immersion of cooling water mist of the whole photovoltaic solar panel array so as to achieve a forced cooling effect.