根据火药破碎度与颗粒间应力的实验关系式，通过计算膛内火药床的颗粒间应力，直接获得不同时刻膛内不同位置的火药床的破碎度，分析了火药破碎对膛内循环过程的影响．指出火药破碎是产生异常压力甚至膛炸的主要原因．研究结果对膛内异常压力和膛炸机理分析以及装药设计均具有重要理论指导意义 According to the experimental relationship between the degree of powder disintegration and the intergranular stress, the degree of fragmentation of the gunpowder bed at different positions in the bore was obtained directly by calculating the intergranular stress of the gunpowder in the bore. The effect of gunpowder disintegration on the circulation in the bore was analyzed . Pointed out that the gunpowder crushing is the main reason for abnormal pressure and even breezing. The results of the study on the abnormal pressure in the bore and breezing mechanism analysis and charge design have important theoretical significance