<p>With the development of HTML5, tracking technologies have evolved dramatically and gradually moved from cookies to browser fingerprinting. Previous research has shown that there are more serious privacy threats associated with tracking behavior on third-party websites. However, by focusing on third-party websites that are loaded in the browser, the researchers overlooked the fact that third-party websites are also present in Android applications, where tracking is easy to perform and definitely covert to detect. In this study, we propose WTDetect, an Android third-party website tracking detection framework. Based on the parsing of view tree and the generation of function call stack, WTDetect automatically locates and captures the source code of third-party websites. To explore the direction of sensitive data flow, WTDetect performs static taint analysis on the program dependency graph for each JavaScript file. Finally, a fine-grained classification model is used to detect the tracking behavior. WTDetect is used to perform a measurement study of tracking behavior on 1090 captured Android third-party websites. The result outlines that 14.68% of third-party websites in Android applications tracking users without any access warnings and user authorization, which directly leads to the risk of privacy leakage.</p>