In this paper, a non-probabilistic Chebyshev convex method (CCM) for the transient dynamics of a dual-disk rotor system with uncertain parameters is proposed. The dynamic equation of the dual-disk rotor system is derived by the finite element method (FEM), and the deterministic response is obtained. Then the CCM is used to obtain the uncertain transient responses of the dual-disk rotor system. The amplitude ranges and response characteristics are quite close to the calculation results of the convex Monte Carlo simulation (CMCS), which verifies the accuracy and validity of the CCM. The experimental results demonstrate that the proposed method has good performance in the uncertainty analysis of the rotor system. More importantly, the results will be helpful to understand the dynamic behavior of dual-disk rotor systems with uncertainties and provide guidance for robust design and analysis.