Abstract: The temperature during the fabrication of wear-resisting functional gradient borides material (FGM) on cast surface was simulated and verified by using ANSYS10.0 program. The simulation results agreed very well with the experimental ones. The process mechanism of wear-resisting FGM at different positions was investigated. The results indicate that the temperature variation at different positions of the gradient alloying powders block will affect the quality of FGM. The temperature of inner and medium layer of block is higher and the duration continues longer, which leads the FGM more strongly. However, because of the temperature quick-drop in the alloy powders block on corners, lower amount in outer layer, many defects and poor quality will proceed. Further results indicate that the thermal conductivity of sand mold and the high fraction of binder alloying for the low melt point in the block will affect the quality of FGM.