Rigid polyurethane formulation with better flame retardancy was designed by changing the type of polyol in the formulation of rigid polyurethane based on current commercial raw materials. Selected high hydroxyl value conventional polyester polyol A， low hydroxyl value conventional polyester polyol B， nitrogen-containing polyester polyol C， chlorinated and brominated flame-retardant polyether polyol D and brominated flame-retardant polyether polyol E were used as the part of the polyol in the formulation. The influence of polyol formulation on the flame retardancy of rigid polyurethane insulation material was studied by testing oxygen index etc. The results show that nitrogen-containing polyester polyol C which contains tris-2-hydroxyethyl-isocyanurate provides rigid polyurethane foam with better flame retardancy property and its oxygen index is 27.5% due to flame retardancy of both nitrogen and polyisocyanurate foam， meanwhile， it is green and low toxic.