With the arrival of the big data era, the currency evaluation of network information has become a spot for today's research. This paper will take Web news as the object of study and study the technology of Web information extraction and Chinese word segmentation in big data environment. On the basis of the above, this paper proposes an algorithm of network information currency evaluation based on Web semantic extraction method. The experimental results fully reflect the validity of the algorithm implementation. The study of technology plays a very important role in leading network users pay attention to more valuable Web information and helping Web site managers build a higher currency network.