A visualization experimental device designed specifically for teaching high school and university physics electromagnetics, which allows students to "see" the Lorentz force acting on moving charges in a magnetic field and complete a complete exploration within 3 minutes. Teaching application: Verify the Lorentz force formula F=qvB sin θ. Explore the quantitative relationship between the radius formula r=mv/qB. Demonstrate the principles of mass spectrometer and cyclotron. Supporting teacher manual, student exploration card, and digital experiment report template. Built in dark box/light shield to eliminate ambient light interference. The base can rotate 360 ° for easy viewing by the whole class. Real time screen mirroring and trajectory recording.