The exploration of shield load distribution rule of large crosssection horseshoeshaped shield and the key design technologies are very important. The axial and circumferential load distribution and transmission rules on shield of large crosssection horseshoeshaped shield used in singletube doubleline railway tunnel are studied; and the numerical model of shield load is established. And then the shield structural design is discussed; the weak point of shield loading is identified; and shield structure is optimized by 3D modeling and finite element analysis. The optimization of the shield structure includes using split combined structure and flange connection to meet the requirements of hoisting and transportation; the beam structure design of box type shell ring ensures the strength requirements, saving material and reducing weight; in addition, the shuttle structure, brim design, advance grouting channel design improve the horseshoeshaped shield’s adaptability. The application of the horseshoeshaped shield and industrial deformation monitoring results indicates the feasibility of the shield system and the validity of the numerical analysis method.