The invention discloses a double-end-face 
numerical control chamfering 
machine tool and method for an ultra-large internal tooth gear. The 
machine tool comprises a 
numerical control rotary table, a horizontal radial sliding table, a first stand column, a second stand column, a Y1 tool rest 
assembly, a Y2 tool 
assembly, a Y3 tool rest 
assembly, a Y4 tool assembly, an X1-axis radial feeding 
system,an X2-axis radial feeding 
system, a Y1-axis vertical feeding 
system, a Y2-axis vertical feeding system, a Y3-axis vertical feeding system, a Y4-axis vertical feeding system, a steel 
brush deburring system and workpiece supports. According to the double-end-face 
numerical control chamfering 
machine tool, the 
motion mode that a workpiece is fixed and the 
machine tool does rotary motion is adopted, the occupied area of the numerical control 
machine tool for chamfering an ultra-large gear is greatly reduced, simultaneous chamfering of the end faces of the two sides of the ultra-large internal tooth gear is achieved through a hard 
alloy milling tool rotating at a high speed, chamfers are adjustable in size and shape, the sizes of the chamfers are consistent, tooth grooves are automatically centered, and deburring and 
polishing work can be carried out on tooth roots, tooth tops and other parts. The 
machine tool is innovative in structure, low in manufacturing cost and high in 
automation degree.