Abstract: The paper studies the profile synthesis in the four axes simultaneous control wire EDM.First, on the basis of the introduction about four axes simultaneous control,two standards of profile synthesis are put forward with the classification of marking in profile. Second, it gives formulas of profile synthesis in each marking condition. Using these theoretical formulas,three dimensional ruled surface with different shapes in top and bottom surfaces can be treated and a four axes simultaneous control program in ISO codes also can be got.

Key words: spark machining, numerical control, cutting, traject or ies, programming