In the Internet era, since online user reviews play an important role in various fields, various industries including real estate industry attach great importance to that. However, according to the existing literatures, there is no clear conclusion that whether online user reviews have an impact on real estate marketing. In order to figure out this problem, this paper will combine traditional real estate theories and machine learning technology to mine data on Chinese real estate online user reviews. We use natural language processing technology and panel data regression analysis method to explore whether the emotional tendency of online user reviews have an impact on the price of second-hand housing in real estate companies, and research more deeply about its impact on marketing of real estate companies. Our research provides a reference for real estate companies to make effective marketing strategies.