Abstract: Designing a new type of steady rest and material rack devices to solve the vibration issue in crank axle of spindle neck lathe turning and gantry robot arm malfunction issue. Basing on Simulation module to topology optimization design in material rack structure which applying in SUC500DHT5 double head CNC lathe, according to the result to verify. Comparing with the original one, the new design weight decrease 31.86%, fundamental frequency decrease 6.64% and the maximum stress reach to 1.214×10⁸ N/m² after topology optimization design, also meet the strength requirements. Experimental results show that the new steady rest structure is stable, fit the crank axle automatic processing. The material rack meets the factor of safety requirements under load applying situation , so the topology optimization design successed.