Fan device for corn harvester

The invention discloses a fan device for a corn harvester. The fan device for the corn harvester consists of a power supply device, an air suction device, a crushing device, a monitoring device and an active obstruction eliminating device; the air suction device and the crushing device are respectively and fixedly arranged on the power supply device; the monitoring device is fixedly arranged on the crushing device; the active obstruction eliminating device is fixedly arranged at the lower end of the crushing device. According to the fan device for the corn harvester, negative pressure is generated in an air suction blade rotating fan drum so as to suck impurities and the straw which is brought by a lift conveyer into the crushing device; blades of the crushing device rotate to crush the impurities, such as the straw; the crushed straw is thrown out of the corn harvester through the air suction device; the straw impurities which enter a peeling machine are reduced; the load of the peeling machine is lightened;