The utility model relates to an aluminum alloy substrate pressing and positioning tool for a mechanical hard disk. The device comprises a base, a positioning rod used for vertically inserting a plurality of aluminum alloy substrates to form a substrate string is vertically arranged on the base, a plurality of aluminum alloy cushion blocks distributed on the substrate string at intervals are further inserted in the positioning rod in an inserted mode, and a pressing mechanism used for pressing the top of the substrate string is arranged at the top end of the positioning rod. The aluminum alloysubstrate pressing and positioning tool for the mechanical hard disk is simple in structure.