Support changing construction method for foundation pit inner support

The invention relates to a support changing construction method for a foundation pit inner support. The support changing construction method comprises the steps that S1, a foundation pit is divided into a plurality of construction areas through a post-cast strip; S2, an inner support structure is constructed in one construction area to support the construction area; S3, a main body structure is constructed in the construction area; S4, in the process of constructing a main body structure beam plate, inclined supports obliquely connected to the main body structure and the inner support structure are constructed at the same time; S5, after the inclined supports and the main body structure beam plate meet the design strength, the inner support structure in the construction area is disassembled; and S6, the inner support structure is transferred into the next construction area, and the steps S2 to S5 are repeated until construction of the foundation pit is completed. According to the support changing construction