Currently, experimental research on variable stiffness design mainly focuses on laminates. To ensure adaptability in practical application, it is imperative to conduct a systematic study on stiffened variable stiffness structures, including design, manufacture, experiment, and simulation. Based on the minimum curvature radius and process schemes, two types of T-stiffened panels were designed and manufactured. Uniaxial compression tests have been carried out and the results indicate that the buckling load of variable stiffness specimens is increased by 26.0%, while the failure load is decreased by 19.6%. The influence mechanism of variable stiffness design on the buckling and failure behavior of T-stiffened panels was explicated by numerical analysis. The primary reason for the reduced strength is the significantly increased load bearing ratio of stiffeners. As experimental investigations of stiffened variable stiffness structures are very rare, this study can be considered a reference for future work.