In the vertical lathe design, there are many methods to realize tapering functions. The vertical turret of single-column mobile vertical lathe is controlled by programmable controller (PLC) and servo control module.It is different from CNC machine tools, still belong to ordinary machine tools.The taper of turning taper is the synthesis of horizontal and vertical direction.The vertical turret, horizontal mechanical chain and vertical direction of mechanical chain is independent, by data processing and horizontal and vertical servo control module, The kind of vertical lathe is through electrical control to guarantee tool tip move according to a taper ratio to realize taper turning.In the PLC dial interface, set the feed rate with the number to solve the problem that potentiometers can not offerlow feed rate.