The invention discloses a catalyst filling structure applicable to a large-tower-diameter catalytic rectifying column and a usage thereof. The catalyst filling structure applicable to large-tower diameter catalytic rectifying column is a rectangular catalyst filling unit formed by alternatively arranging catalyst packages of various structures and regular filling materials, wherein each catalyst package is formed by stitching multiple small catalyst packages which are vertically arranged. During using, reaction sections of the catalytic rectifying column are set in multiple layers, each layer is provided with multiple catalyst filling units; adjacent catalyst filling units and two adjacent catalyst filling units at the upper layer and the lower layer are arranged in a manner of staggering from each other by 90 degrees; and granular fillings are filled in gaps in the column wall. According to the invention, catalyst packages in the catalyst filling unit is flat, so as to effectively reduce diffusion resistance inside the catalyst packages to fully utilize surface areas of the catalyst granules to improve catalyst utilization ratio; and the catalyst filling units are arranged in a staggered way to facilitate even distribution of vapor and liquid. At the same time, sizes of the catalyst filling units disclosed by the invention can be flexibly set according to actual column diameter, so as to facilitate in-column assembly, maintenance and replacement.