The machine design is to devise an adjustable vertical double-headed drilling machine. The design mainly introduced the design principle, adjusting and design calculation process for devise a adjustable vertical double-headed drilling machine. Through the processing requirements given in advance can determine the computation parameters, then based on the design principle, which is about adjustable vertical double-headed drilling machine, to design ,calculate and check each place parts, and then to assemble all the parts. The design can be devised from five aspects. Through the processing requirements given in advance，five parts of the design, the adjustable double transmission system, design of the reducer drive system for the motor selection, design of X-Y workbench, design of axial feeding system for drill bits, can be calculated and devised. Through design and assembly of the drilling machine, two holes can be formed after one processing, and the distance between the two holes can be adjusted. So as to realize processing some groups of holes with different space between two holes. Adjustable vertical two-headed drilling machine can multiply processing efficiency without increase human and equipment, and can guarantee a high machining accuracy and precision of the relative position between holes.