Abstract: The main form of the turn-milling motion and the characteristic of the turn-milling are expounded, and the excellence and the localization of the axial turn-milling and the orthogonal turn-milling are introduced briefly. The uniform vector model of the turn-milling motion is founded, and the vector expression of the turn-milling motion that is the same with the axial turn-milling and the orthogonal turn-milling and so on is educed, and the vector expression of turn-milling motion is discussed in-depth.

Key words: Turn-milling, Turn-milling motion, Vector expression