The LaxHo2-xFe17 (x=0.0, 0.2, 0.4, 0.6, 0.8) powders were prepared by arc melting and high energy ball milling method. The influence of the La substitution on phase structure, morphology, magnetic properties and electromagnetic parameters were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating-sample magnetometry (VSM) and vector network analyzer (VNA), respectively. The results show that the saturation magnetization increases and the average particle size increases with the increase of La content. The minimum absorption peak frequency shifts towards a lower frequency region with the increase of La content. The minimum RL of La0.2Ho1.8Fe17 reaches -28.72 dB at 8.72 GHz, and the frequency bandwidth of R<-10 dB reaches about 2.32 GHz with the best matching condition d=1.8 mm. The reflection loss with the thickness ranging of 1.2-2.4 mm could reach -10 dB, which indicates the particles be considered as the promising microwave absorbing materials with better absorption properties.