Did tycho brahe develop his own theory

if he did can you explain it in a simple way?

Yes, he did. For example, he developed a theory that "new stars" (now know as supernovas) where not atmospheric phenomenon, but were high above the atmosphere and way past the moon. He also developed a theory that comets were above the atmosphere. And he had a theory that the planets (except the Earth) revolved around the sun.

Then there is his theory of the moon's orbit, which fit the observations five time better than previous theories.

yes he did.