For the morbidity of addition and subtraction inverse operation for the interval grey number, the relationship of
modulus on both sides of the operation equation is analyzed. A kind of optimize operator is introduced, and it’s accuracy
and precision are proved. Based on the grey incidence degree theories, the computing method for the degree of interval grey
number incidence is developed by use of the optimize operator. Meanwhile, incidence decision problems of multi-attribute
interval grey number are studied, and the incidence decision making model of multi-attribute interval grey number is set up.
Finally, examples illustrate the effectiveness and practicability of proposed model.