Based on the forced vibration experiment principle, the effect of the forced vibration initial phase on experimental measurement results is discussed. MATLAB is used to visualize the analytical solutions and amplitude-frequency characteristics under different resistance torques for forced vibration. Taking students as the center and problem oriented, students are guided to analyze the physical mechanism of the operation process during the explanation of experiment principle by means of MATLAB visualization, which can strengthen the experimental inquiry ability of student. Some achievement about the teaching reform has been achieved in teaching practice.