Horizontal supporting method for basement side wall earthwork in-advance backfilling

The invention relates to the technical field of building construction, and discloses a basement side wall earthwork advanced backfilling horizontal supporting method which comprises the following steps: S1, chiseling weak concrete of a beam plate at a horizontal jacking position of a settlement post-cast strip; s2, manufacturing a back shore steel plate; s3, preparing a jacking piece; s4, mounting and reinforcing a horizontal back shore; and S5, checking and accepting. According to the basement side wall earthwork advanced backfilling horizontal supporting method, under the condition that the settlement post-cast strip is not closed, the technical measure of horizontal jacking in the post-cast strip is adopted, basement side wall earthwork is backfilled in advance, the project earthwork outward transportation engineering amount is reduced, meanwhile, the basement side wall earthwork is backfilled in advance, and a risk source is eliminated. Furthermore, material transportation and personnel passing are not in