i'm wondering how if all the countries in this world forbid of using and doing the transaction of bitcoin including buy and sell and convert it to fiat currency in all the country in this world, what will gonna do, is it will be the end of bitcoin or is there any solution if it happen
How many things are actually forbidden in all of the countries in the world? As a general rule, it doesn't happen. Even if something is forbidden in most or all countries, some countries are less strict on those prohibitions. For example, most of the world respects copyrights as defined by the Berne Convention and their own laws implementing that, most of the world also has similar concepts of patents and trademarks (with exceptions, like America's insane idea of software patents that some parts of the world don't recognize). However, it isn't hard to set up a business in certain countries, China for example, making counterfeit goods that obviously violate copyrights, trademarks and patents and you aren't likely to ever be prosecuted for it. Another example would be drug laws, in most of the developed world there is a prohibition on marijuana, but there are still places you can go to buy it and use it legally even with pressure from the United States (the most powerful country in the world militarily, and at one time economically as well) to strictly prohibit it everywhere. There are even places in the United States now where you can buy it and use it "legally" according to state law in spite of what federal law says.
I can't think of too many things that are universally prohibited worldwide and strictly enforced in most or all jurisdictions.. murder might be a good example, but beyond that, every country has its own laws and its own priorities.
There's also the well known and indisputable fact that there is a certain percentage of people who will do what they want and don't particularly care about what the law says. The history of gun control laws, drug prohibition and alcohol prohibition in the U.S. and other jurisdictions prove that. I can't legally own an AK-47 in California (a real one, not a semi-auto with fixed magazine), but I know where I could get one if I wanted it bad enough. I can't legally grow, own or use marijuana without a doctor's recommendation in California, but there are literally millions of people doing those exact things. At one time you couldn't legally own, use or manufacture alcohol for drinking purposes anywhere in the United States, I think we all know how that turned out.
Even if, by some miracle of almost unprecedented international cooperation/conspiracy, Bitcoin were somehow banned worldwide, there would still be a thriving black-market as long as there is demand for it. There will also always be people who use it for otherwise "legitimate" online purchases as long as there's someone who will accept it.
some Countries just don't give a shit .
Biggest country on Africa and situated on North Africa . 
