Subsea manifolds are important equipment for offshore oil and gas extraction. The layout of the manifold is related to both the difficulty of fabrication and the installation and maintenance of the manifold. Based on 1500 m deep sea conditions and 68.9 MPa pipeline fluid pressure, the overall design of a double well groove and double collector subsea manifold is investigated, the selection of specific parameters is discussed in detail. The arrangement of different valves and pipelines and the efficiency of space volume usage are discussed. Stress analysis of the designed manifold as a whole was carried out using AutoPIPE software and its strength was assessed according to the applicable American Society of Mechanical Engineers (ASME) standards. It was found that the maximum stress ratio was 0.9 for radial stresses and relatively small for axial stresses, but both met the design requirements for deep sea manifold piping. Finally, linear and nonlinear buckling analyses of circular arc pipes were carried out, the fifth-order linear eigenvalue buckling modes, linear critical buckling load and nonlinear critical buckling load were obtained. It is found that the nonlinear critical buckling load was 20.5% lower than the linear critical buckling load. The failure mode of post-buckling is local dimple, which is located at the initial defect, indicating that early geometric defects have a greater influence on the load carrying limit of the pipe. This paper can provide a reference for the study of common technologies for the design of deepwater subsea pipeline manifolds and subsea production facilities.