How to get your world back if you died in minecraft game?

Were you playing in hardmode? Because then, you can't. If you aren't and the world crashed or just isn't working, you can take a save state of it on a USB or some other storage device. Then try again.

Are you playing on hardcore? If so, no there isn't.

If you died in your Minecraft world, you can always click on the "Respawn" button to respawn at your spawn point. If however, you're playing hardcore mode, sorry; your world is gone forever.

If you are in Hardcore mode there's nothing you can do, the world is gone. If you are in any other mode you should be able to just respawn.