Combination machine tools based on general parts, according to the specific shape of the part and process design of special components and fixture, composed of dedicated semi-automatic and automatic machine tools. 
It usually USES the shaft, knife, or transfer process and surface processing ways at the same time, the production efficiency is higher than general machine tools several times or more.Because general parts have standardization and seriation, can according to need to be flexible configuration, can shorten the design and manufacturing cycle. 
Therefore, both the advantages of low cost and high efficiency of combined machine tool, widely used in large, mass production, and can be used to form an automatic production line. 
Combination machine tools are used for processing box or special shape parts.When the workpieces are generally not rotate, by the rotation of the cutting tool movement and relative feed movement, cutting tool and the workpiece to achieve drilling, reaming, counter boring, reaming, boring, plane, internal and external thread cutting and milling machining cylindrical and end face, etc. 
Some modular machine tool by turning head clamping workpiece rotation, by cutting tool feed movement, also can achieve some revolving body parts (such as flywheel, vehicle driving axle half shaft, etc.) of the cylindrical and face processing. 
Special machine tool is with the rise of the automobile industry and developed.Some part in the special machine for repeated use, gradually developed into general parts, creating a combination machine tools. 
In order to make the combination machine tools can be applied in the medium and small batch production, often need to apply group technology, the structure and process of similar part focused on a modular machine tool processing, in order to improve the utilization rate of machine tools. 
There are two kinds of this kind of common machine tool, can be combined in spindle box combination machine tools and turret machine tools.