The invention relates to an evaluation method for early damage of an additive manufacturing part based on 
metal magnetic memory detection and belongs to the field of 
metal magnetic memory detection innondestructive detection, wherein a 
mechanics theory and a force-magnetic 
coupling theory of ferromagnetic materials are used for guiding, and the variation condition of a residual magnetic inductionintensity standard deviation and a residual magnetic induction intensity gradient maximum value thereof along with the tensile load is used as an early damage 
state representation method of the additive manufacturing part. The residual magnetic induction intensity of the additive manufacturing part under different stretching states is detected by adopting a 
metal magnetic memory method, the earlydamage change process of the defect is characterized by the change of magnetic memory signals, and the residual magnetic induction intensity standard deviation and the 
residual magnetic field intensity gradient maximum value are used for representing the early damage situation of the additive manufacturing part. According to the method in the invention, the metal magnetic memory detection technology is combined with 
damage mechanics, the 
magneto-mechanical effect of the ferromagnetic additive manufacturing part is used to achieve nondestructive detection of the early damage of the ferromagnetic additive manufacturing part under the condition of not requiring magnetizing, and the judgment accuracy is high.