Why my iPhone switch off it self

Hello Naomi4040,

It looks like you joined the Apple Support Communities from the following Apple page: iPhone Battery and Performance - Apple Support. If you were having issues with the battery on your iPhone, this is a very helpful article.

Make sure that the iPhone is taking a charge and that there are no issues with the charger. Make sure you are charging your iPhone with a known working charger. If this does not help to resolve the issue, you'll want to force restart your iPhone to see if this helps you to get the iPhone started. Here's guidance on how to force restart your device: Force restart iPhone - Apple Support.

If the issue remains, try connecting your device to a computer and completing the following steps under the section labeled "If your iPhone turns on but gets stuck during start up": If your iPhone won't turn on or is frozen - Apple Support.

We hope this information helps you out.

Kind regards!