I want to block magnetic field of the very strong magnet, can I put it inside faraday cage to block its magnetic field?
No. The point of a Faraday cage is that it's made of a conductor, which responds to electric fields. A strong magnetostatic field is different, and will barely be affected by the Faraday cage. (The cage may have some magnetic properties, but that's not what makes it a Faraday cage, and it's unlikely to have a significant impact.)
There's a little info on Wikipedia about magnetic shielding: http://en.wikipedia.org/wiki/Electromagnetic_shielding#Magnetic_shielding