Rigid polyurethane foam(RPU) was synthesized using isocyanate,polyether polyols,chain extender,crosslinking agent and accessory ingredients as raw materinals.The related influence factors on the foaming properties were discussed.The experimental results show that the amount of isocyanate,water and 1,1-dichloro-1-fluoroethane(HCFC-141B) plays an important role in the density,structure and mechanical properties of RPU.When water of 1.25 g,HCFC-141B of 33.54 g,isocyanate of 155.01 g and flame-retardant agent of 22.59 g were added into 100 g of premixed polyether polyol,the polyurethane rigid foam exhibited good compressive strength and dimensional stability.Tris(2-dichlorpropyl) phosphate can improve flame resistance of RPU.