A material for repairing a historic building wall comprises components as follows: 5%-10% of a modified material and the balance of backfilling soil. A construction technology for repairing the historic building wall comprises steps as follows: 1), clearing is performed on a bottom terrace of a foundation pit, no sundry exists on the backfilling soil, and 5%-10% of the modified material is added into the backfilling soil; 2), the backfilling soil is paved and spread in a layering manner; 3), each layer of backfilling soil is at least rammed for three times, later ramming is performed in the half position of previous ramming, later ramming and previous ramming are performed continuously row by row, and ramming is performed in a vertical and horizontal crossed manner; 4), a wall in a region is rammed and cast once, and filling and ramming are performed in the deep position first when the deep and shallow positions are connected, and filling and ramming are performed in the deep and shallow foundations when soil is backfilled to the same height with the shallow position; if filling and ramming are required to be performed sectionally, the interaction position is filled in a stepped manner; each layer of backfilled soil is required to be flat after rammed and cast; 5), after each layer of backfilling soil is rammed, sampling is performed through a cutting ring, the mass density of dry soil is measured, and soil paving is performed on an upper layer after the requirement is met; and 6), trimming and leveling. The material for repairing a historic building wall has the characteristics of high mechanical strength, long durability, wind and rain corrosion resistance and simple construction method.