<p>The parameters having a strong influence on a bending performance of composite I-beams were analyzed. Firstly, an analytical model of the bending mechanical properties of composite I-beams was established, and the precision of the model was verified through the tests. Secondly, based on the model proposed, the dimensional and material parameters of composite I-beams were selected, and the adaptive sparse polynomial chaotic expansion agent model was used to perform sensitivity analysis of buckling load and ultimate load. The results showed that the dimensional parameters have a higher sensitivity to the buckling load and ultimate load compared to the material parameters, and the analysis procedure proposed is generalizable and can be applied to other structures.</p>