Abstract: Abstract: As one of the important biomass resources in China, straw plays an important role in energy utilization. While straw solidifying technology provides an effective utilization route which has been widely used. After densification, both density and intensity of the straw fuel were improved, making it easier to transport, store and use. And this efficient utilization is also crucial for providing bio-energy, releasing the risk of environmental pollution caused by crop straw burning. But there are still some problems, such as easy wear of ring die, which will shorten its service life. In this paper, the wear behavior of ring die has been studied based on experimental test and theoretical analysis. After the shape of the worn ring die was tested, the microscopy morphology was obtained by scanning electron microscopy (SEM), and then the wear mechanism was analyzed. By testing it is found that abrasion mainly occurs in the middle part and lower side of the die, and abrasion gradually weakens along the feed direction. Hard abrasive wear plays a leading role in the wear process; the material loss of the die surface is caused by the cutting fracture mechanism. According to conclusions above, the calculation model of this abrasive wear was deduced based on fractal theory. It shows that the wear rate of the ring die is related to the particle size silhouette coefficient G, contact area Ar, forming speed v and material properties. Then the effect of the forming speed and the hardness of the ring die to this abrasive wear was investigated by using finite element analysis software DEFORM. The forming speed was set as 7, 8, 9 and 10 mm/s four levels, and the die hardness was set as 42.5, 45, 47.5 and 50 HRC four levels. The forming temperature was 110℃ while the extruded material length was 45 mm. Simulation results show that the wear depth of the ring die increases with increasing forming speed and decreases with increasing die hardness. Range analysis results of the above two factors are RHRC=2.846, RV=1.822, RHRC >RV, which means that die hardness plays a more important role than forming speed to the die wear. To verify these conclusions, 45 steel dies were divided into four groups for heat treatment to obtain different hardness (36.2 HRC, 42.8 HRC, 47.9 HRC and 52.6 HRC). The heat treatment method was tempering after whole quenching, different hardness was achieved by controlling the tempering temperature. Then these ring dies were installed into the machine for production testing after being weighed and the forming speed was set as 9 mm/s. The experiment results indicate that the wear resistance of the ring die increases with increasing hardness, while the die hardness is between 36.2 and 47.9 HRC. Because it is more difficult for the abrasive to press into the metal with a higher die hardness. Its brittleness will be enhanced if the surface hardness is too high for the same material, this may lead to die failure directly under the high pressure working environment. The die with a hardness of 52.6 HRC was broken shortly after the experimental test started. While the forming speed is 9 mm/s, the interior of the fuel combines relatively close, and the product density is 0.96 g/cm3 with a better ignition performance. In addition, the fractal dimension of the worn working surface decreases with increasing die hardness.