Abstract: Based on the basic principle of flux locus control,then a new type of full digital control PWM inverter by 8098 single chip microcomputer is designed.The equilateral 60-side polygon of flux control is adopted in this system.A new method of instantaneous cutting of zero vector insertion is presented,instead of the fixed insertion method.It saves the storing space of table,improving the real-time nature of control.And the switching frequency of inverter is regulated automatically.