The invention discloses a cooling tower energy-saving device. According to the technical scheme, the cooling tower energy-saving device is characterized by comprising a shell, wherein a water pipe with a vertically upward pipe port is arranged in the shell, a spraying adapter which can horizontally rotate is arranged on the water pipe, branch water pipes are connected to the side face of the spraying adapter, and a self-assistant air guide device used for assisting in air convection is arranged on the upper portion of the spraying adapter. According to the cooling tower energy-saving device, while water current impact force provided by a circulating water pump of a cooling tower is used for driving a spraying device to rotate, the self-assistant air guide device is driven to rotate, hot air convection is promoted, a draught fan is omitted, energy consumption is reduced, the structure of the cooling tower is simpler, and maintenance is easy to perform.