Abstract: Due to environmental corrosion, material aging, and frequent lifting operations, the safety of aged crane operations on platforms has received great attention. How to quickly and effectively evaluate the bearing capacity of offshore crane structures is an urgent problem that needs to be solved in current offshore platform lifting operations. This article developed a structural testing system for offshore platform cranes, which includes strain and vibration testing using a water bag lifting combination; Research on finite element model correction method based on measured structural response data; Developed a model-based evaluation technology for the structural load-bearing capacity of offshore platform cranes. Taking the aged crane of a certain platform in the South China Sea as an example, the static and dynamic responses of the crane structure under multiple angles were measured through the small load lifting function test of the crane. Based on the measured response data, the model was modified and a benchmark model of the tested crane structure was established. The simulation and strength calculation were carried out according to the design load specified in the standard. At the end of the article, the bearing capacity curves of the crane from various angles are provided to guide safe lifting operations on site.