A semi-rigid riveted structure with large openings is proposed for the payload cabin of the Mengtian lab module on the China Space Station. The integrated design of structural bearing， load engress and ingress，and load test platform is achieved. In view of the effects of factors such as the flight of the ascent stage and the ground lifting load，the numerical simulation method is used to analyze the structural strength iteration， identify the potential weak links of the structure， and carry out targeted local structural tests to verify the weak links. Finally，a static test platform with large openings is designed and built，and the whole cabin static test is implemented. The numerical calculation and test results are in good agreement，verifying the correctness of the design for the payload cabin with large openings. The design methods and verification ideas of the payload cabin structure can provide references for other aircraft structures.