We study the renormalization group flow of the continuum model (BM model) for the twisted bilayer graphene and obtain the RG flow equation for the Fermi velocity and the interlayer couplings. Under RG, the system flow towards the chiral limit, revealing the relation between the ideal chiral limit and the realistic system. In addition, we apply the DMRG numerical method to study the spin and valley polarized BM model with the projected Coulomb interaction. At the half filling, three different phases, QAH, gapless nematic, and gapped stripe states, strongly compete with each other. Interestingly, the stripe phase is C2T symmetric, but open a gap by breaking the translation symmetry. We propose this phase as a possible candidate for the ferromagnetic insulating state with vanishing Hall conductivity observed at \nu = 3.