The invention discloses a key die machine. The key die machine comprises an upper die assembly and a lower die assembly, wherein the lower die assembly comprises a face shell placing box, a key placing box, a housing and a base plate; the housing is fixedly arranged on the base plate; the inner side of the side wall of the housing is step-shaped; the face shell placing box is arranged at the bottom of the step in the housing, and is in sliding fit with the base plate; the bottom of the step in the housing restricts the sliding direction of the face shell placing box; the key placing box is arranged on the first floor of step surface in the housing and is in sliding fit with the step surface; the second floor of step in the housing restricts the sliding direction of the key placing box; a key slideway for passing of keys is arranged on the key placing box; the upper assembly comprises an adjusting block, a die block and a power assembly; the adjusting block is arranged above one of ends of the housing; the face shell placing box and the key placing box slide to the end in the housing to be corresponding to the adjusting block; and the die block is arranged above the adjusting block.