For the problem that the interval grey number can not make full use of decision information, on the premise of information without losing, the interval grey number is decomposed into the real type sequence of“white sequence”and“grey sequence”based on the information decomposition method. The advantages and disadvantages of existing vector projection decision-making methods are analyzed. The bi-directional projection method is constructed based on the positive and negative ideal point and solution points vector measure. And the consistency coefficient of the bi-directional projection decision-making model is proposed. Finally, the numerical example is given to illustrate the feasibility and effectiveness of the proposed model.