摘要：【中文】本发明属于固体火箭发动机技术领域，具体涉及一种固体火箭发动机用聚苯乙烯喷堵及其发泡方法。该方法利用蒸汽发生器产生的高温蒸汽加热发泡模具，使可发性聚苯乙烯受热发泡成产品形状。通过控制蒸汽温度、压力和流量实现快速发泡，实现了低密度喷堵的发泡。与水煮工艺相比，该工艺发泡率高，发泡时间短，生产效率高。 【EN】The invention belongs to the technical field of solid rocket engines, and particularly relates to a polystyrene spray plug for a solid rocket engine and a foaming method thereof. The method utilizes high-temperature steam generated by a steam generator to heat a foaming mould, so that the expandable polystyrene is heated and foamed into a product shape. The rapid foaming is realized by controlling the temperature, pressure and flow of the steam, and the foaming of the low-density spray plug is realized. Compared with the water boiling process, the process has the advantages of high foaming rate, short foaming time and high production efficiency.