The learning interest plays an important role in the specialized course teaching activities, and it is also one of the most important parts which the teacher should pay attention. This paper gets related data through questionnaire survey, analyses the relationship between students' interest of specialized course and its influencing factor by using of rough set theory and provides theoretical foundation for how to improve students’ interest in specialized course teaching activity by analyzing the importance degree quota of all the factors. My RS results show that teaching level of professional course is the most important factor to improve college students’ learning interest. Using the analysis result about the influence on college students specialized course learning interest, A novel teaching model can be established on the course of Digital Signal Processing Technology. Through contrast on the actual teaching situation between traditional teaching class and experimental teaching class, as well the results of questionnaire survey. The paper analyzes with the old and new teaching model, the students’ changes from their specialized course learning interests, the actual testing scores, professional characters results, etc. The experimental results show that in this item, the analysis about the influence on college students specialized course learning interest is very important to improve college students specialized course learning, which are in accordance with the theoretical analysis.