Abstract: In considering the interaction between the spin and lattice case, the relation between dynamic dimer and magnetic coupling coefficient was analysized with the density matrix renormalization group method when a onedimensional blocked frustrated Heisenberg antiferromagnetic spin chain model occurred SpinPeierls phase change. The results demonstrated that when the magnetic coupling coefficient tends to 0, the dimerization state would disappears in the state for the zero coupling between the limited and finite energy gap.