With the rapid development of the size of government micro-blog users and its influence, the function of governmental earthquake micro-blog communication platform has become more and more important. In this paper, under full consideration of the characteristics of the seismic sector, we collected the information from 30 governmental earthquake micro-blogs, and used the principal component analysis(PCA) to analyze the main influence of three kinds of governmental earthquake micro-blog indicators. We have established an evaluation index system for the influence of earthquake official micro-blog, in which the indexes include principal component of service force, principal component of interaction force and principal component of creation force. We have calculated the principal component of seismic micro-blog influence index score and the composite score. Finally, based on the score, we proposed a feasible strategy to improve the influence of the governmental earthquake micro-blogs.