This article analyzes the impact of the rise time and overshoot values on the calibration results of voltage dividers. Taking a 3600 kV impulse voltage generator as an example, the study examines the different superimposed overshoot values when the generator outputs impulse voltage waveforms with varying time parameters. When the generator’s output rise time approaches 0.84 μs, the test waveform exhibits significant overshoot (11%). However, when the output waveform time is 1.3 μs, the overshoot value decreases significantly (1.9%). The study further performs convolution calculations based on the voltage divider’s step response waveform to analyze the output waveform parameters under different input waveforms. The results indicate that the impact of overshoot values on the calibration ratio of voltage dividers is more pronounced than that of time parameters. Even with significant differences in rise time, the calibration test results for the divider ratio remain unaffected when the test waveform exhibits no noticeable overshoot. In conclusion, for on-site high-voltage impulse voltage tests, it is advisable to use test voltage waveforms with smaller overshoot values. If necessary, the rise time can be increased to greater than 1.56 μs to ensure accurate calibration results for the voltage divider.