Abstract: Using phenol, urea, and paraformaldehyde as the raw materials, and the toughening agent polyvinyl alcohol (PVA) and cashew nut shell liquid are added to prepare phenol urea aldehyde (PUF) resin, and the resin is subjected to a foaming test to prepare PUF foam for use in mining empty area along goaf air leakage control.Comparative analysis of the effects of the toughening agent polyvinyl alcohol (PVA) and cashew nut shell liquid on PUF foam shows that the introduction of polyvinyl alcohol (PVA) and cashew nut shell liquid as toughening agents can significantly enhance the toughness of the foam.When the toughening agent is compounded (the ratio is PVA∶cashew nut shell liquid=1∶1) and the amount is 2.5%, the powdering rate of the foam is reduced by 22%, and the density and compressive strength are increased to 0.11 g/cm³ and 15 kPa respectively. The foam cells are the most dense and complete under the microstructure.