The invention belongs to the technical field of a cast-in-situ skeleton, a preparation method of the cast-in-situ skeleton and a building made of the skeleton and discloses the cast-in-situ skeleton,the preparation method of the cast-in-situ skeleton and a structural wall prepared from the skeleton. The cast-in-situ skeleton is mainly technologically characterized by comprising a first membrane shell located on the outermost side, wherein keels are stuck on the inner side surface of the first membrane shell, and each keel comprises at least two parallel sticking planes; second sticking planeslocated on the inner sides of the keels adhere to the outer side surfaces of thermal-insulation boards; an outer pull rod is arranged on the first membrane shell located between every two adjacent keels, an inner pull rod is arranged on the inner side of the outer pull rod, a second sticking piece is arranged on the inner side of the inner pull rod, a second membrane shell is stuck on the secondsticking piece, and a pull rod connecting piece with an outer connecting end and two inner connecting ends is arranged between the inner pull rod and the outer pull rod. The direct casting can be performed after supporting is finished, processing and mounting are convenient, a large number of formworks are saved, construction cost is reduced substantially, procedures of wall plastering and concrete curing are omitted after forming, cost is saved, and construction waste is reduced.