The system data just take all my iPhone storage

It is not possible to delete System Data.

System Data contains, among other things, cache files from both iOS and your apps, which make your apps start faster, which saves on the battery, since the apps don't have to load everything from the start again. As written, System Data cannot be deleted, but over time, iOS itself will start to clean up when there is a lack of space. For example during a software update. It will also clean up a bit when the phone restarts.

If you lack space, see if there is a new update ready, or see what is taking up space, and possibly delete what you don't use here: Settings → General → iPhone Storage.