The invention relates to the technical field of grain boundary diffusion type neodymium iron boron component analysis, and discloses a component analysis sample preparation method of grain boundary diffusion type neodymium iron boron, which comprises the following steps of S1, neodymium iron boron pretreatment, S2, grain boundary diffusion type neodymium iron boron preparation, S3, grain boundarydiffusion type neodymium iron boron selection, S4, cleaning and drying, S5, sample crushing, and S6, sample analysis and sample preparation. According to the component analysis and sample preparationmethod of the grain boundary diffusion type neodymium iron boron, component analysis and sample preparation are conducted on the grain boundary diffusion type neodymium iron boron through six steps ofS1, neodymium iron boron pretreatment, S2, grain boundary diffusion type neodymium iron boron preparation, S3, grain boundary diffusion type neodymium iron boron selection, S4, cleaning and drying, S5, sample crushing and S6, sample analysis and sample preparation, the step process is simple, and operation is easy. Meanwhile, the flaky sample is converted into powder in the step S5, digestion treatment in the step S6 is facilitated, the sample digestion process is more sufficient, the time is shorter, and the component analysis and sample preparation time is greatly shortened.