Targets are physical base of laser inertial confinement fusion (ICF) research, whose quality has extremely important influences on the reliability and degree of precision for subsequent ICF experimental results. At present, the degradable mandrel technique with poly-α-methylstyrene (PAMS) degradation as the core has become one of the key technologies for fabricating ICF target. Its general process can be divided into three steps: first, hollow PAMS microspheres are prepared as mandrel, then plasma vapor deposition technology is used to prepare a coating (glow discharge polymer, GDP) with higher thermal stability on the surface, and finally PAMS are degraded leaving the hollow GDP target. Although many reports have been devoted to the related process, there are still two key problems in the actual preparation of GDP, that is, how to reduce the thermal degradation temperature of PAMS and how to avoid residues in PAMS degradation. Considering that the general nature of degradation corresponds to the breaking of chemical bonds, it is urgent to grasp the physical laws of the complex degradation process of PAMS at the atomic level and construct the reliable model of mandrel degradation.