The invention discloses an automatic oil collecting device of coolers of transformers. The automatic oil collecting device of the coolers of the transformers comprises multiple oil collecting funnels, an oil collecting tank and an oil storage device. Each oil collecting funnel is fixed to the position below an oil discharging hole of the corresponding cooler of the transformer through a movable connecting piece and communicates with the oil collecting tank through a connecting pipe. The oil collecting tank transfers oil to the oil storage device through an automatic transferring device. Oil discharging operation is conducted on the multiple coolers at the same time through the multiple oil collecting funnels, so that the oil discharging efficiency is greatly improved. The oil collecting funnels are arranged on the coolers through the movable connecting pieces and are convenient to detach and repeatedly use. Long-distance operation of the oil collecting funnels is achieved through the connecting pipe, and therefore the problem that installation of the oil collecting tank is inconvenient is solved. Oil is transferred through the automatic transferring device, so that labor intensity is lowered, and the transformer oil is prevented from being sprinkled.