The invention discloses an internet public opinion analysis method. The internet public opinion analysis method comprises the steps of firstly for selected and acquired events, partitioning a source text of a microblog and removing partition items unrelated to sentiments; secondly making statistics by adopting a statistic analysis tool to obtain an input of a sentiment classification model; and finally for the input, modeling related words, expressions and symbols capable of expressing the sentiments in the microblog content by using a classification algorithm, giving out comprehensive sentiment index assessment, obtaining sentiment categories, and performing public opinion monitoring and sentiment trend analysis. According to the method, the words, the expressions, the symbols and the like in the microblog are subjected to sentiment modeling, and the response situations of hot events in the microblog can be automatically classified and effectively monitored through sentiment index calculation, so that the public opinion risk can be effectively assessed and intemperate events can be prevented and controlled.