A method for preparing a substrate structure of a memory, comprising: providing a substrate; forming a first mask layer on a surface of the substrate, a plurality of strip patterns extending in a same direction and spaced apart from each other being provided in the first mask layer; forming a first dielectric layer covering the first mask layer; patterning the first dielectric layer to form a plurality of sacrificial portions spaced apart from each other, the sacrificial portions covering the strip patterns; filling gaps between the sacrificial portions with a second dielectric material; forming, by removing the sacrificial portions while retaining the second dielectric material in the gaps, a second mask layer, with through-hole patterns exposing the strip patterns formed in areas that correspond to the sacrificial portions in the second mask layer; and performing layer-by-layer etching into the substrate by using the first mask layer and the second mask layer as masks to transfer the strip patterns and the through-hole patterns to form a plurality of active areas arranged in an array, wherein patterning the first dielectric layer to form the plurality of sacrificial portions spaced apart from each other comprises: forming a plurality of first through-holes distributed in an array in the first dielectric layer; characterized in that, (S 1302) forming a plurality of second through-holes distributed in an array in the first dielectric layer, the first through-holes and the second through-holes are alternately arranged in both a first direction and a second direction perpendicular to the first direction, and an orthographic projection of any first through-hole on the substrate is in contact or overlaps with an orthographic projection of a neighboring second through-hole on the substrate in the first direction and the second direction, wherein a portion of the first dielectric layer between any two neighboring first through-holes in a third direction forms the sacrificial portions, and a deviation angle of the third direction relative to the first direction is π/4. providing a substrate; forming a first mask layer on a surface of the substrate, a plurality of strip patterns extending in a same direction and spaced apart from each other being provided in the first mask layer; forming a first dielectric layer covering the first mask layer; patterning the first dielectric layer to form a plurality of sacrificial portions spaced apart from each other, the sacrificial portions covering the strip patterns; filling gaps between the sacrificial portions with a second dielectric material; forming, by removing the sacrificial portions while retaining the second dielectric material in the gaps, a second mask layer, with through-hole patterns exposing the strip patterns formed in areas that correspond to the sacrificial portions in the second mask layer; and performing layer-by-layer etching into the substrate by using the first mask layer and the second mask layer as masks to transfer the strip patterns and the through-hole patterns to form a plurality of active areas arranged in an array, wherein patterning the first dielectric layer to form the plurality of sacrificial portions spaced apart from each other comprises: forming a plurality of first through-holes distributed in an array in the first dielectric layer; characterized in that, (S 1302) forming a plurality of second through-holes distributed in an array in the first dielectric layer, the first through-holes and the second through-holes are alternately arranged in both a first direction and a second direction perpendicular to the first direction, and an orthographic projection of any first through-hole on the substrate is in contact or overlaps with an orthographic projection of a neighboring second through-hole on the substrate in the first direction and the second direction, wherein a portion of the first dielectric layer between any two neighboring first through-holes in a third direction forms the sacrificial portions, and a deviation angle of the third direction relative to the first direction is π/4. forming a plurality of first through-holes distributed in an array in the first dielectric layer; characterized in that, (S 1302) forming a plurality of second through-holes distributed in an array in the first dielectric layer, the first through-holes and the second through-holes are alternately arranged in both a first direction and a second direction perpendicular to the first direction, and an orthographic projection of any first through-hole on the substrate is in contact or overlaps with an orthographic projection of a neighboring second through-hole on the substrate in the first direction and the second direction, wherein a portion of the first dielectric layer between any two neighboring first through-holes in a third direction forms the sacrificial portions, and a deviation angle of the third direction relative to the first direction is π/4.