The invention discloses a solid acid catalyst with high reaction activity, a preparation method therefor and an application of the solid acid catalyst. The catalyst comprises the ingredients in partsby weight: 100 parts of support, 18-36 parts of sulfonic group, a zinc group with 8-16 parts of activated zinc, a zirconium group with 10-20 parts of activated zirconium and an aluminum group with 7-14 parts of activated aluminum, wherein the sulfonic group is chemically connected to the support, and the zinc group, the zirconium group and the aluminum group are chemically connected to and/or physically attached to the support; and the support 1 is of an organic carbon skeletal porous structure, and a unit structure of the support 1 has a chemical formula: 1,4-di[di(3-carbazolyl)-methyl]benzene. A catalytic reaction is carried out through acid and active sites loaded by a carbon radical skeleton, and the catalyst has high catalytic activity during HDI synthesis; and meanwhile, the catalysthas the advantages of easiness in recovery, low cost and no corrosion to chemical equipment.