Impact abrasive wear behavior of thixo-injecting forming hypereutectic high Cr cast iron billets by conventional sand casting and by slope cooling semi-solid casting was analyzed. The results show that slurry fluidity is greatly decreased due to coarse rod-like carbides in conventional as-cast billets, which results in surface rough and internal shrinkage hole in thixo-injecting forming parts, meanwhile, matrix is obviously fragmented by coarse rod-like primary carbides, and the carbides are broken off during wear process, leading to the deterioration of wear resistance. Slurry exhibits acceptable fluidity during thixo-injecting forming process as a result of fine primary carbides in slope cooling semi-solid billets, which leads to smooth surface and low internal defects in the parts, meanwhile, primary carbides and eutectic carbides show fine and uniform, resulting in the low cutting role in matrix and uniformly surface wear, which are responsible for the improvement of wear resistance.