With the arrival of the informationization era, the inheritance and development of ethnic folk dance in dance teaching faces new challenges and opportunities. This paper discusses effectively inheriting and developing ethnic folk dance under informationization. The research methodology includes the Analysis of folk dance movement characteristics, movement capture and feature extraction based on Kinect acquisition technology. The results show that the dancer’s movement data can be accurately recorded by Kinect capture technology, and the error of capture coordinates can be minimized up to 1.115. The study also finds that the dance movement features can be effectively extracted using Gaussian Mixture Model Background Subtraction and Median Filtering preprocessing techniques. In addition, the “Trinity Teaching Assistive Technology” proposed in this study can improve teaching quality. The application of information technology not only promotes the scientific and standardized teaching of folk dance, but also helps improve students’ skills and creativity.