Abstract: In this paper, the preparation process and performance characterization of natural rubber modified by casting dust (XJ01)-gas phase silica were studied. XJ01 and fumed silica as reinforcing agent, zinc oxide and stearic acid as active agent, anti-aging agent 4010, accelerator DM and sulfur as raw materials, double-roll mill and flat vulcanization Rubber samples of different formulations were prepared. The particle size of the foundry dust before and after the modification was studied by using the multifunctional particle size and morphology analyzer. The Fourier transform infrared spectrometer was used to study whether the foundry dust was modified. The morphology of the fumed silica and the changes of micro-morphology of different formulations was studied by transmission electron microscopy, scanning electron microscopy, electronic tensile testing machine and dynamic mechanical analyzer. The results show that casting dust can improve the dispersibility of white carbon black in natural rubber and improve the compatibility of white carbon black with natural rubber. XJ01 can partially replace white carbon black to reinforce natural rubber, thereby reducing the use of white carbon black, reducing the environmental pollution caused by foundry dust.