The recycle of wasted thermoplastic polystyrene was used as the matrix mixing with the wasted PET, foaming agents, and flame retardants. The sample of wasted fiber board were fanned by the mixing and hot pressing. The immersion effect, their mechanical properties and the best treatment conditions of the cellular material were studied. The results indicate that the best treatment condition is found to be PET25%、ADCAO.9g、and flame retardants15%.