The key technologies of rectangular pipe jacking machine used in pedestrian passageway on South Renminlu crossing underneath Sichuan University in Chengdu with waterrich sandy cobble strata are studied. The structure of the cutterhead is optimized by finite element simulation analysis method ANSYS Workbench so as to explore the technology of excavating rectangular crosssection using multicutterhead arranged 〖JP〗on a same plane.The boxtype with four spokes + ringform support is adopted for the cutterhead which can meet the strength requirements and improve the opening rate. The thickness of the screw blade of double screw conveyor is optimized by ANSYS simulation analysis. The industrial test shows that the screw conveyor with large diameter and large pitch can effectively improve the mucking effect of large diameter cobble (larger than 450 mm). In addition, the orthogonal test is used to carry out soil conditioning; and proper ground conditioning scheme is obtained.