End mill cutting tools are widely used in machining of curved surface parts in many areas, e.g. aerospace, automobile, and energy. The parameters of helical groove cross section, influencing chip removal capacity, include rake angle, core radius and edge width. Towards a parametrical control algorithm of the cutting tool flute, this paper proposed an iteration based method. Within the context, the cutting tool parameters and grinding wheel are set firstly. Then, three angle parameters, alpha, beta, and theta in the grinding coordinate system, are looped. In each loop, one of the target flute parameters is compared with the pre-set values, and if the parameter is within the range, the calculation goes the next loop until the parameters are in the target range. Since the loop number is so high that the computing time is too long, the patterns between the flute parameters and looped parameters are used to improve the calculation speed. The method is implemented by using C#, and validated by a set of numeric simulation based on Matlab (R).