After completing a project in DaVinci Resolve, you can free up disk space by removing temporary files that were created to improve playback and editing performance.
Start by clearing the render cache:
Playback → Delete Render Cache → All
Next, go to Project Settings → Master Settings → Working Folders and note the location of your Cache files directory. Open that location in your file explorer and delete the CacheClip folder to remove any remaining cached media.
Don’t forget to empty your Trash to complete the cleanup and reclaim the space.