Ablatable flame-retardant layer of solid rocket engine, preparation method and application of ablatable flame-retardant layer

The invention relates to an ablatable flame-retardant layer of a solid rocket engine as well as a preparation method and application of the ablatable flame-retardant layer. The ablative flame-retardant layer is prepared from the following raw material components in parts by mass: 35 to 45 parts of hydroxyl-terminated polybutadiene, 6 to 8 parts of di (2-ethylhexyl) sebacate, 0.025 to 0.05 g of dimethyl silicone oil, 2 to 3 parts of a chain extender, 0.15 to 0.2 part of a curing aid, 40 to 55 parts of a high-heat-sink filler, 5 to 8 parts of a curing agent and 0.6 to 0.8 part of a dibutyl phthalate solution; wherein the dibutyl phthalate solution contains ferric acetylacetonate with the mass percentage content of 2.0%-2.5%; the flame-retardant layer is arranged between the first-stage propellant and the second-stage propellant and has flame-retardant and ablation effects, the first-stage propellant is ignited in the solid rocket engine to achieve heat absorption, ablation and strength loss of the flame-retarda