how to deal with this prof when he gives you his lowest grade? Now our marks came out and the average is 94 and he gave me 2 marks less than the average of the class. (This means that I have got the lowest grade in the class)

I am overthinking these days and getting a headache.
I really want to figure out what is his intention and why is he playing with my future?

I always study hard to get everything done in high quality; I always compare my work with other classmates to correct myself; I do not know why he gave me his lowest grades? 

Should Ph.D. students get higher than master students? is there any range?
or 
I am getting this just because I am a girl...
You should assume the grading is fair, unless there is a reason to believe otherwise. Based on your question and comments, I don't see any reason to believe that discrimination is involved.

You state that you did everything that was required, just like the other students. That doesn't mean you should get exactly the same grade as them. Perhaps your presentation was not as clear as the others or your project had some minor flaws. It is very hard for you to judge that yourself -- you are neither an expert like the professor is nor objective in self-evaluation.

You received a 92, which is below the class average of 94. To me, that still sounds like a good grade and you shouldn't be concerned. Trying to argue for every last point is not productive -- it's called grade grubbing.