Experiments were conducted to evaluate the progressive collapse resistance of a scaled partial double-layer latticed Kiewitt-6 (K6) dome in member-removal scenarios. The test results were compared with results obtained previously for a single-layer latticed dome to demonstrate the advantages of the partial double-layer members for improving the collapse resistance. A finite element (FE) analysis was also executed to confirm the experimental observations and to evaluate that the collapse-resistant behavior of a full-scale partial double-layer latticed dome. The collapse-resistant mechanism of partial double-layer domes was examined via theoretical analysis. On the basis of these results, a novel cable-stiffened partial double-layer latticed dome was proposed. The results indicated that the tested dome did not completely collapse, but some of the upper chord members buckled. For the whole dome, the compression mechanism is regarded as the major load-carrying mechanism to resist progressive collapse. In terms of the local area around the failed members, the adjacent members initially rely on the beam and compression mechanisms to resist progressive collapse. As the number of the failed members increases, the adjacent members completely rely on the beam mechanism to resist progressive collapse. The FE results agree well with the experimental results. The progressive collapse-resistant behavior of partial double-layer domes is far superior to that of single-layer domes because of the better stiffness of the partial double-layer members. The cable-reinforced partial double-layer dome is a novel structural system that has significantly better progressive collapse-resistant behavior than traditional single/double-layer and partial double-layer domes.