A portable manual vertical milling key duplicating machine comprising a body, a main axis component, a guide component, a clamping component, a feeding component, a power storage unit, a display unit and an electric control unit. This solution provides a pre-positioned precise guide mechanism and an adjustable handrail and is capable of improving the precision of key processing in multiple aspects and increasing stability during key processing. It has a compact structure with an upper/lower separate two-way sliding table configuration, thereby substantially reducing the machine size, and the body is divided into three areas, thereby ensuring good protection.