First, open the editing application and import the video to be edited. In the main interface, find and click the "Start Creating" button to enter the material library. Select the video file to edit from the material library, and then click Add to import it into the timeline.

Second, in the timeline, find the clip that needs to apply slow-motion special effects, select it and drag it to the video track below. You can determine the start and end points of slow-motion special effects by sliding the timeline or adjusting the length of video clips on the track.

3. In the editing interface, find and click the "variable speed" option. In the speed change interface, you can see that the default speed change multiple is 1, indicating normal speed. To apply slow-motion effects, you need to adjust the movement ratio to a value less than 1. Sliding the variable speed slider to the left can slow down the video playback speed, thus achieving the slow motion effect.

According to the need, adjust the speed change multiple to an appropriate value to complete the setting of slow-motion special effects.

Four, after the completion of the speed setting, you can choose to view the slow-motion effect in the preview window. Click the play button at the bottom of the preview window to watch the slow motion effect of the whole video. If you need to further adjust the slow motion effect, you can continue to adjust the position of the variable speed slider until you are satisfied.

5. After setting the slow-motion special effects, you can click the "Export" button to export and save the edited video. In the export interface, parameters such as video resolution and frame rate can be selected to ensure that the exported video quality meets the requirements.

You can do some advanced settings for slow-motion special effects. In the speed change interface, you can choose the option of "curve speed change" to control the speed change of slow motion effect more flexibly by adjusting the curve nodes. You can further edit and adjust slow-motion clips, cut and add transition effects in the timeline.