What should I do if the fork in the middle of the lock cylinder of the anti theft door is wide

Two things to explain, the first thing, don't oil the lock cylinder, no oil will work, then the lock cylinder will not work directly. The second thing, this situation is generally caused by the friction between the marbles or blades and the key, you can get some special lubricant for the lock cylinder (look for it on the Internet, there are a lot of them), or you can use the powder of the 2B pencil lead (scrape it off with a knife) on the key, gently reach into the lock cylinder, twist it a few more times and use it.

First of all, I recommend you! Use the tool to take it out slowly. The first thing to see if the toothpick has room to move, and then follow these steps: >>>More

If you can, you can raise the indoor temperature and you can avoid it. The simple way is to lubricate the lock cylinder with pencil foam. If you really can't open it. >>>More

Find a professional lock shop master to help you come to the door to overhaul and then replace the broken part.

It may have been used for a long time and there is wear and tear, you can remove it and apply grease to try No, only replace the new lock body.