The invention relates to a system and method for rotary hearth furnace iron making through coal rapid pyrolysis coupling. The system for rotary hearth furnace iron making through coal rapid pyrolysiscoupling comprises a coal rapid pyrolysis system and a rotary hearth furnace reduction ironmaking system; the coal rapid pyrolysis system comprises a low-rank coal crushing device, a low-rank coal drying device, a downer rapid pyrolysis device and an oil-gas separation and purification device; the low-rank coal crushing device is connected with the low-rank coal drying device, the low-rank coal drying device is connected with the downer rapid pyrolysis device, and the downer rapid pyrolysis device is connected with the oil-gas separation and purification device; the rotary hearth furnace reduction ironmaking system comprises a raw material pretreatment device, a forming device, a pellet drying device and a rotary hearth furnace device; and the raw material pretreatment device is connectedwith the forming device, the forming device is connected with the pellet drying device, and the pellet drying device is connected with the rotary hearth furnace device. With adoption of a method for rotary hearth furnace iron making through coal rapid pyrolysis coupling, the cost and energy consumption of steel smelting are reduced, and comprehensive utilization of upgrading of low-rank coal is achieved.