To kill the ender dragon with a bed, you need to install a one-cycle platform. You can do this by placing a bed on top of a rock pillar, then placing two obsidian blocks on one side, then blowing it up trying to use it. You'll also need at least eight or ten beds to kill him with – we recommend bringing a few more in case you mess up.
That being said, you can kill the Ender Dragon by blowing up the beds using them at the right time. This timing will be the right timing when the ender dragon swoops down on the bed, but to get the timing right you should probably use it a bit before its head is about to hover over the bed.
You will also need to target the central part of the dragon's head, as this is where it will take the most damage. Fortunately, you can do this if you wait for the right time, but if you need more help, check out Josh The Squash's awesome guide that will be linked above.
For more on Minecraft, check out What are the Distant Lands in Minecraft? and how to install shaders in minecraft
