In this paper, the representative local part of the membrane roof in 2010 Shanghai EXPO central axis is chosen to carry out the full-size experiment. First, the mechanical properties of PTFE coated fabrics are studied according to the biaxial stress-strain curves under five stress-ratios. The ultimate capacity of single-layer model and double-layer model are got by piling sandbags. The numerical simulations are presented to compare with the experiment data. Results show the material strength, joint strength, and tension protocols agree well with the design. The failure of two models can be considered as material failure. The ultimate capacity of double-layer model is about 1.8 times the single-layer one. The differences between experiment data and numerical simulation are large, because the constitutive relationship used in numerical calculation differs with the practice.