本文对某压缩机气缸所用毛坯进行了断裂分析,首先通过常规应力的计算,找出应力最大点,以此选取半椭圆裂纹、单排并裂贯穿裂纹群和圆片裂纹群三种裂纹模型,算出裂纹的临界尺寸a_(cr),并以无损探伤的结果确定初始裂纹尺寸a_0,以此为条件分别进行了线弹性和弹塑性的寿命分析。最后,对气缸毛坯存在缺陷问题,提出了一些看法。 In this paper, the fracture analysis of the blank used in a compressor cylinder is carried out. Firstly, the maximum stress point is found through the calculation of normal stress. Three kinds of crack models, ie, semi-elliptical crack, single row and split through crack group and wafer crack group, The critical crack size a_ (cr) was calculated, and the initial crack size a_0 was determined by the result of non-destructive flaw detection. Linear elasticity and elasto-plastic lifetime were analyzed respectively. Finally, the cylinder blank defects exist, put forward some views.