hi every one
how can I double my btc ??

Fastest and the riskiest way = Gamble it on a dice game with 2x payout. Do it only if you can afford to lose your btc. If you ask for safe way, trading might be the right thing to double your btc.
this is lose way not double way

if you see gambling like that, you can try trading but if you still see trading as losing money maybe you are looking for HYIP investment scheme here? if so, you will just probably lose more money there than in gambling