The invention relates to an air gap insulating material for an iron core reactor, an air gap cushion block for an iron core reactor and an iron core reactor. The air gap insulating material for the iron core reactor is mainly made from the following raw materials in parts by weight: 30-35 parts of unsaturated polyester resin, 5-6 parts of an initiator, 30-35 parts of a filling material, 10-11 parts of a thickening agent, 5-6 parts of an internal releasing agent and 17-20 parts of a reinforcing material. The air gap cushion block for the iron core reactor is manufactured by adopting the above materials. The dry-type iron core parallel reactor is manufactured by using the air gap cushion block. The iron core reactor adopts the SMC material based air gap cushion block for the iron core reactor, thereby being capable of well reducing the noise and vibration at the air gap, and thus being capable of significantly reducing the overall noise and vibration of the product. The noise and vibration are very small when the product is in operation, and the competitiveness of the product in the grid field market is improved.