Abstract: To solve the problem that traditional cast steel materials are difficult to adapt to the complex working conditions of shearer rocker arms, this paper adopts a multi-alloying design idea, optimizes the contents of basic elements C, Si, and Mn, compound adds Cr and Ni alloys to develop a new type of high-reliability cast steel material, and optimizes the supporting preparation process. The results show that the material (C: 0.26-0.32%, Si: 0.35-0.60%, Mn: 1.00-1.40%, Cr: 0.30-0.50%, Ni: 0.30-0.40%, P and S ≤ 0.025%) has a tensile strength of ≥920MPa, a yield strength of ≥780MPa, an impact toughness of ≥38J/cm² at -20℃, and a welding carbon equivalent of 0.51-0.68. Compared with the traditional ZG25Mn material, its strength is increased by 31.6%, impact toughness by 46.4%, and wear resistance by 63.1%. The 18-month industrial test shows that the failure rate of the rocker arm made of this material decreases from 11.1% to 1.8%, and the maintenance cycle is extended by 185.7%, which can effectively ensure efficient and safe coal mining.