In view of the multi-objective decision problem that the attribute values are interval grey numbers and the attribute weights partially known, the multi-objective decision-making method based on the kernel and the degree of greyness of the interval grey numbers is proposed. Considering the scope of the expert evaluation, the domain of discourse and the simplified forms of the interval grey number based on the kernel and the degree of greyness of grey numbers are given. The conversion method from the ordinary interval grey numbers to standard grey numbers is designed. The attribute weight vector is solved respectively based on the kernel and the degree of greyness of the standard grey numbers. An ordering method based on the relative kernel of the standard grey numbers is proposed and is used to sort the project. Finally, an example is given to illustrate the feasibility and effectiveness of the proposed method.