The FeWB alloy powders were successfully obtained from reactive synthesis, and the bulk materials were prepared by the spark plasma sintering (SPS) technique using the FeWB alloy powders. The influences of temperature and holding time on the microstructure of alloy powders, as well as the reaction mechanism were investigated by X-ray diffraction meter (XRD), scanning electron microscopy (SEM), energy disperse spectroscopy (EDS) and Lakeshore 7410 vibrating sample magnetometer (VSM). The results show that increased temperature and extended holding time are both beneficial to synthesizing the phase FeWB. The boron and iron atoms diffused into tungsten particles to form W2B and Fe2B firstly, and the FeWB alloy powders were obtained at 1150°C after holding 3h. The bulk materials exhibit the Rockwell hardness of 90.4HRA measured by an HR-150A Rockwell hardness tester which could be comparable to the hardness of cemented carbides. FeWB alloy presents a promising future in the hard material area.