This paper has further derived the formula of the VSS computation on the basis of the former research, obtained a general method in theory of calculating the VSS of the country and every department. And then, taking the departments of manufacturing industry in 2004 as an example, the article has combined the criteria for classification of input-output table and SITC, used the programs of the Matlab and calculated the VSS of the eight departments. The calculating course and the result prove that: introducing new computing method and classification criterion, it reduces greatly the difficulty of calculating the VSS, theoretically and technologically. This paper contributes much to the further research for a clear thinking.