I need some advice

Hii I have 9 month baby and German citizen and we live together with my wife and my baby they are both German but I am illegal here in Germany so can I get work permit so long as my child and wife is German I already got vatershaft am responsible of the child
And back 2015 I get deported from Germany to Spain so long us I got fingerprints immigrants over there and my asylum case was over so I come back and got baby here so can I stay legally here?

As far as I know, there is no way of converting illegal stay into legal (other than applying for political asylum, which you already tried unsuccessfully). Thus it was NOT a good idea to come back illegally!
The only advice I could give you is returning to Spain (or any other country where you can stay legally) and applying for a family reunion visa at the German embassy there. This should be easy for a father of a German citizen - IF the authorities don't know that you are here illegally now.
For any other method, better engage a good immigration lawyer and don't expect it to be easy!