In this paper, the root causes of bead toe cracking of steel radial tire were analyzed. It was found that the key issue was the poor air exhaust in the position of mold to form bead toe. Based on the analysis, arc connection was used to replace the straight line connection between the slope of steel rim molding position and the platform of bead toe molding position. Air vent holes were designed in the connection part of the mold to improve the air exhaust during the molding process.