Abstract: Polyvinyl alcohol(PVA) capsule layer, as a gas barrier, were developed for the inertial confinement fusion(ICF) program. This paper presented the simulation study on fabrication of PVA coating using drop-tower technique. Based on the heat, mass and momentum transfer of the transformation process, a physical model was established and the related mathematic model was developed. The influence of processing parameters on the transformation was simulated. The key processing parameters that greatly affected the gel-to-shell transformation and the resulting PVA properties had been found to be initial PVA concentration, PS diameter, furnace temperature profile and thermal conductivity of the furnace gas.