Abstract: To reduce the mass of the pitch support of the furnace-front operation robot while maintaining its structural performance under extreme working conditions, a parametric lightweight design study was carried out. Equivalent loads at the connection positions of the pitch support were obtained from the static analysis of typical operating postures of the whole robot, and local finite element models were established for a rotary driving condition and an extreme impact condition. According to the structural characteristics of the component, the main plate thickness, stiffener width, web position distance, web thickness, and chamfer angles of the front and rear edges were selected as design variables. The mass of the structure was taken as the objective function, and the maximum total deformations under the two load cases were taken as constraints. Latin hypercube sampling was used to generate sample points, and a second-order response surface model was constructed for the mass and deformation responses. A genetic algorithm was then employed to search for the optimal solution. After engineering rounding and finite element verification, the mass of the optimized pitch support decreased from 513.7 kg to 441.7 kg, corresponding to a reduction of 14.0%. The maximum total deformations under load cases A1 and A2 were 0.35 mm and 0.97 mm, respectively, both within the allowable range. The maximum equivalent stress remained below the yield strength of Q355B steel. The results indicate that the present parametric optimization procedure is effective for the lightweight design of the pitch support and can provide a useful reference for the design of load-carrying components in heavy-duty industrial robots.