The hinged door of the large-scale, horizontal container is usually deformed and distorted during the process of assembly and long-term usage, which can prevent the door from closing tightly and thus affect the sealing performance. A novel single-axis-double-pin hinged door was developed for a 5.5-meter-diameter, large-scale chamber, which was under construction for the plume experiment in vacuum. The design and analysis was conducted for the rotating mechanism, the restrictive switch device, as well as the elastic support unit at the bottom of the flange. The finite element method (FEM) was finally adopted to check the structural requirements. The results shows that the y-direction displacement, caused by the gravity, is the main factor of the combined displacement of the door. At the junction of the hinge and the flange, the range of the concentrated stress will shrinks, and the value of stress will decline, if a elastic support force is exerted at the bottom of the flange, which also ensures the combined displacement of the door less than 10mm. The strength and stiffness requirements are satisfied for the single-axis-double-pin hinged door. This work will provide insight for the future design of the similar scale hinged door.