Abstract:In this paper, the theoretical models and influencing factors of fatigue short crack propagation at home and abroad in recent decades are reviewed, the shortcomings of the elastic model of short crack propagation are discussed, the elastic-plastic mechanical parameter j-integral is introduced to describe the stress field at the tip of short crack, and the new research methods are discussed, which combining macroscopic mechanics and the concept of micro-mechanics, analyze the propagation rule of short crack. In view of the special non-propagation crack in the short crack stage, the causes of the crack are discussed, and the difference between the fatigue strength reduction coefficient Kf and the theoretical stress concentration coefficient Kt is explained. The influence of the geometry, notch plastic zone, microstructure and test environment on the short crack propagation is introduced. At last, the author further confirmed the unique "V" type propagation law of short crack by studying the propagation law of main crack and secondary crack in the experiment, and tried to explain the non-propagation crack behavior of short crack by observing the whole process of crack propagation and using the change of crack tip stress field.