Due to the characteristics of domestic mountainous terrain, the tunnels are increasing. Therefore, an increased budget and more advanced equipment are required to maintain the tunnels cleanliness. As a study on shape optimization using the design of experiment, this paper assessed the design parameters affecting the maximum stress of an articulated hydraulic crane boom. As a result, the maximum stress of an optimized boom was 223.94 MPa at optimal factors. It showed an accuracy of 99.38% compared with the finite element analysis.