Nano-barium ferrite BaFe13O14 was prepared by self-propagating combustion synthesis. XRD, SEM and Laser Granularity Analyzer were used to characterize the structure, micrographic morphology and particle size of products. The results show that the purity of products is very high. It belongs to hexagonal crystal structure and magneto plumbite type ferrite. Their particle size is below 50 nm. In order to research the ability of electromagnetic wave adsorption, electromagnetic parameters were measured with vector network analysis from 2 similar to 18 GHz, and the tangent value of electromagnetic loss was calculated. Accordingly, the mechanism of electromagnetic wave adsorption was explained. At last, the 8 mm wave (36 GHz) attenuation tester was used to measure the property of reflection and transmission. The results show that barium ferrite BaFe13O14 has a favorable property of electromagnetic wave adsorption in the range of centimeter and millimeter waves. The products can be applied in the field of stealth technology and military camouflage.