Aimed at the severe problems in tokens and computations of grey numbers, which expanded unnecessarily and distorted the information heavily, this paper defined the standard interval grey number and the first and the second standard grey number, and analyzed their relationship. Furthermore, it designed the transformation rule from general grey number to the standard interval grey number, and developed the operation principle of the standard interval grey number to solve preferably the above problems. Last, the paper established the GM (1,1) model based on the interval grey number and got a good effect.