Abstract: Disclosed are a mold assembly for making alkali metal wax packets, a method for preparing same, and a method for using same. The mold assembly comprises a silicon substrate (10), the silicon substrate (10) comprising a mold isolator (11) at the edge of the silicon substrate (10) and a silicon substrate central portion (18). The upper surface of the silicon substrate central portion (18) is indented to form a plurality of wax packet receiving cavities (12). A cavity isolator (13) locates between adjacent wax packet receiving cavities (12). A release sacrificial layer (15) is formed on the upper surface of the silicon substrate (10), and a paraffin layer (16) is formed on the upper surface of the release sacrificial layer (15) away from the silicon substrate (10). Cavities (121) for containing alkali metal are formed on a side of the paraffin layer (16) away from the release sacrificial layer (15). The mold isolator (11) is provided with corrosion release holes (14).