Form grinding is one of the most efficient processes for finish machining of gear wheels. This paper investigates the method of system development for wheel modification of involute cylindrical gear based on SINUMERIK 840D system and its OEM development package. The control software developed for form grinding is applied to dress form grinding wheel by using the numerical control dresser, and normal projection is adopted as the method to calculate the sectional shape of grinding wheel. The friendly interface of control software, edited by Visual Basic was developed to meet needs of users. Finally, personalized interface and processing methods are integrated and embedded in Siemens CNC system through Dynamic Link Library to implement parameterized automatic processing, which is more efficient in programming and machining.