Big Redstone Door is a huge kind of door in the Minecraft game. You can use a lever on both the dies and then connect them using redstone dust. Go through this guide and follow step-by-step instructions to make one.
In order to make a Big Redstone Door, place twelve pistons on the ground in the same way as shown in the image below.
Fill the gap in front with 2 gray concrete blocks and then add more concrete blocks in front of it.
The next thing you have to do is add a layer of concrete blocks at the top and join them by placing the gray concrete blocks in between.
Add a lever at the front side and two redstone repeaters at the top. And then connect the repeaters with this lever with the help of redstone dust.
The door is complete now. Pull the lever down to close the door and pull back again to open it.
Now you need to add a lever on the opposite. Go to the other side and add a lever, pull this down to close the door again.