The so-called grey decision-making is a mathematical method that can solve the grey numbers in the system. The community is full of uncertainty that needs to be resolved. Although there are a lot of decision-making methods being used, the purpose of this paper is to provide a new decision-making mode to eliminate the uncertainty, so that the decision-making can be more complete. The main point is to integrate the grey generating and globalization grey relational grade in the grey system theory in order to suggest a new analysis from the traditional grey decision making analysis and provide a supplement. This paper also makes use of the case of 'purchasing a house' and the proposed mathematical mode to do the grey relational grade method analysis in order to get the best decision making result.