Limiting structure and fixing device used for penetrating through floor slab steel sleeve

The utility model relates to the technical field related to building installation, in particular to a limiting structure and a fixing device used for penetrating through a floor slab steel sleeve, thelimiting structure comprises a stand column and a plurality of abutting plates arranged on the outer side of the stand column, and the abutting plates are connected with a first adjusting mechanism arranged in a first cavity in the stand column; the first adjusting mechanism drives the plurality of abutting plates to diffuse or fold; one end of the stand column penetrates through the formwork andis limited through a threaded assembly, a pressing plate is installed at the other end of the stand column in a sliding mode, the pressing plate is connected with a second adjusting mechanism arranged in a second cavity in the stand column, and the second adjusting mechanism drives the pressing plate to move in the axial direction of the stand column. And therefore, the steel sleeve is axially limited in cooperation with