The invention discloses a staple cartridge assembly and a medical stapler using the staple cartridge assembly. The staple cartridge assembly comprises a connector, a cutter push rod and an elastic sheet, the elastic sheet having a first through groove and the cutter push rod being formed by laminating multiple sheets, wherein when the staple cartridge assembly is in an original status or a closed status, part of the cutter push rod is located in the first through groove, and the first through groove restricts detaching of the multiple sheets in a laminating direction of the multiple sheets； in a firing process of the staple cartridge assembly, the cutter push rod moves towards a distal end of the staple cartridge assembly to press the elastic sheet, such that the elastic sheet deforms and the cutter push rod is gradually detached from the first through groove； after the firing of the staple cartridge assembly is finished, the cutter push rod is detached from the first through groove. By restricting the multiple sheets using the first through groove in the elastic sheet in the present invention, the multiple sheets will not detach from one another in a laminating direction thereof.
