The invention relates to a catalyst filling member of a catalytic rectifying tower and application thereof. The catalyst filling member is composed of a cylindrical shell, an anti-overflow baffle plate, a lower bottom panel, and a separating plate. The catalyst filling member is characterized in that the anti-overflow baffle plate positioned in the middle of the cylindrical shell divides the cylindrical shell into a gas phase channel and a catalyst filling area, wherein the anti-overflow baffle plate is made of an impervious flat plate, and the height of the anti-overflow baffle plate is 0.6-0.8 times that of the side wall of the cylindrical shell 1; that the lower bottom panel positioned in the lower bottom of the catalyst filling area is composed of a wire screen plate or a porous plate, and the separating plate prepared by a wire screen plate or a porous plate is positioned on the anti-overflow baffle plate flatwise, wherein the area of the separating plate equals to that of the cross section of the cylindrical shell, and a structured material-filling area used for filling materials is arranged on the separating plate; and that multiple filling members are arranged by layer, wherein the gas phase channels and the catalyst filling areas of two members which are arranged vertically are in staggered arrangement in the tower, and in-tower members in two vertically neighboring layers are superposed in the same axis. In the filling member, the surface areas of catalyst particles can be effectively used, the utilization rate of the catalyst is improved, the pressure drop of the bed layer is reduced, and the capacity of mass transferring and separating is strengthened.