This work uses the GHZ state as the initial state and selects the minimum quantum relative entropy as the entanglement measure. Based on these settings, various traditional dynamical decoupling methods are systematically compared. The results reveal significant limitations in their ability to preserve entanglement under a local Markovian environment. To overcome these limitations, we first investigate non- \(\pi \) pulse control strategies. These strategies induce the system to evolve toward more stable entangled states by modifying the structure of the density matrix. On this basis, three structural stability principles closely related to entanglement preservation are summarized, and two structurally optimized states, \(|\psi _{\text {robust1}}\rangle \) and \(|\psi _{\text {robust2}}\rangle \) , are constructed accordingly, successfully achieving the preservation of entanglement structure in the three-qubit system.