Abstract: The course “Signals and Systems” plays a crucial role in the knowledge system of electronic information majors as a fundamental course. An integrated classroom pratical teaching of “frequency domain analysis method” is designed, which is an important method in the cource, and propose a visual teaching approach based on a unificed system platform for three domain analysis problems, including the response of linear and time invariant system to the deterministic signal, Nyquist sampling theorem and signal reconstruction based on sampled signal. Through independent practice, students can visualize and perceive theoretical knowledge, and in this process, they can realize reverse reasoning verification and achieve the goal of self-perception. Practical teaching in class not only enables students to have a deeper understanding of the knowledge points, but also effectively stimulates their interest in learning this course. Statistical data shows that after introducing classroom practical teaching, the average score of this course has increased from less than 80 to over 90 points, with an average score increase of 18.60%. The proportion of outstanding students in the comprehensive evaluation results has increased by 257.12%, reflecting good teaching effectiveness.