Visualization is the theory, technology, and method of using computer information technology to convert data into graphics or images, and then to interact with humans. In this chapter, the application scenarios of visualization teaching have been discussed based on numerical simulation technology, following the aspects of topic selection, theoretical analysis, numerical calculation, and result discussion. Python software is used to study the impact of release height, launch angle, and drag on the trajectory of projectile motion, as well as the changes in light diffraction for different obstacle shapes. And the graphical reproduction and result analysis of projectile motion trajectories and diffraction light intensity distribution under different conditions are achieved, by using the tools of Python script and Jupyter Notebook. The results show that whether it is script program or the Jupyter notebook, Python’s rich text editing capabilities and interactive interface features can achieve both adjustable parameters for problem research and visibility of results. The application of visualization technology makes the thinking process concrete and personalized in problem discussions, and changes the classroom teaching model from “closed” to “open.” Visualization teaching is not only conducive to learners’ understanding of the essence of principles and laws, but also effectively promotes the enhancement of creative thinking abilities, which makes the teaching methods of basic physics courses greatly enriched.