Several non-dimensionalization changings of single-index data sequence and their characteristics are studied in this paper. An improvement model on degree of grey slope incidence is developed. The improved one can reflect the positive and negative relation of sequence and by the model the value of the degree and coefficient of grey incidence does not change with any non-dimensionalization processing on the raw sequence. At the same time, the characteristics of the degree and the coefficient of grey incidence are studied. It is found that this method makes good use of the information of every timetable and its correlation of positive or negative, and the result of grey incidence analysis by this method is more scientific than before and is easier to calculate on the computer.