user43221: Is there any tool for Bitcoin blockchain decompiling?
I see news about Ethereum Decompiler, but is something like for Bitcoin?

user57657: There is a big different between the language used by the bitcoin blockchain and the one used in ethereum.
Ethereum smart contract programmers usually write their code in a high level language (such as solidity) and then compile it into hard to read bytecode.
Bitcoin script programmers write the code in a language that is not compiled, like if they were writing the bytecode itself (it isn't actually a bytecode though).
So it is logical that you can't decompile a language that was never compiled in the first place.
The thing you can do is look at the hexadecimal representations of bytes in a bitcoin script and check which operation they represent.
This page has the list of all the commands and their hex value.
Edit
When you write a script in Bitcoin it is already fully transparent. It never  gets compiled, NEVER. It is already fully transparent because you never compile it. You don't need to decompile it because it was never compiled, just like you can't destroy an house that was never built in the first place. 
Did I already mention that you don't need to decompile because the code never gets compiled?
Because it is really important to understand that it never gets compiled. You can just read it as it is.
If you see a 0x6a in the code it reads like OP_RETURN as for the link i gave you above. You can read through the whole list of hex charachters in a script and decode it like that. There is nothing more you can do
I hope it will be clear now.

43221: <p>Is there any tool for Bitcoin blockchain decompiling?</p>

<p>I see news about <a href="https://www.coindesk.com/first-ethereum-decompiler-launches-jp-morgan-quorum-integration/" rel="nofollow noreferrer">Ethereum Decompiler</a>, but is something like for Bitcoin?</p>
 57657: <p>There is a big different between the language used by the bitcoin blockchain and the one used in ethereum.</p>

<p>Ethereum smart contract programmers usually write their code in a high level language (such as solidity) and then compile it into hard to read bytecode.</p>

<p>Bitcoin script programmers write the code in a language that is not compiled, like if they were writing the bytecode itself (it isn't actually a bytecode though).</p>

<p>So it is logical that you can't decompile a language that was never compiled in the first place.</p>

<p>The thing you can do is look at the hexadecimal representations of bytes in a bitcoin script and check which operation they represent.</p>

<p><a href="https://en.bitcoin.it/wiki/Script#Words" rel="nofollow noreferrer">This page</a> has the list of all the commands and their hex value.</p>

<p><strong>Edit</strong></p>

<p>When you write a script in Bitcoin it is already fully transparent. It <strong>never</strong>  gets compiled, <strong>NEVER</strong>. It is already fully transparent because you <strong>never</strong> compile it. You don't need to decompile it because it was <strong>never</strong> compiled, just like you can't destroy an house that was never built in the first place. </p>

<p>Did I already mention that you don't need to decompile because the code <strong>never gets compiled</strong>?</p>

<p>Because it is really important to understand that it <strong>never gets compiled</strong>. You can just read it as it is.</p>

<p>If you see a <code>0x6a</code> in the code it reads like <code>OP_RETURN</code> as for the link i gave you above. You can read through the whole list of hex charachters in a script and decode it like that. There is nothing more you can do</p>

<p>I hope it will be clear now.</p>
