Aiming at the complex situation of vehicle suspensions affected by multi-source uncertainties, a dynamic characteristic analysis method for the air suspension systems considering hybrid uncertain parameters is proposed. Firstly, a hybrid uncertain model was adopted to characterize the multi-source uncertain parameters of air suspension system. The parameters with insufficient information were treated as interval variables, while those with abundant information were described as random variables. Then, the orthogonal polynomial expansion approximate model of the random and interval mixed uncertainty system response was established within the unified orthogonal polynomial expansion theory framework using the derived λ-PDF, and a method that can effectively solve the mixed polynomial coefficients was derived. The dynamic characteristics of air suspension were quickly calculated through the constructed mixed polynomials. Furthermore, to verify the effectiveness of the proposed method, a reference method based on the Monte Carlo approach was presented. Finally, the effectiveness of the proposed method was verified by example analysis and the system response results under different uncertain situations were explored. The analysis results show that the proposed method can effectively solve the dynamic response of system and has higher computational accuracy and efficiency, compared with the reference method based on Monte Carlo simulation. The proposed method is superior to the existing hybrid perturbation subinterval method in solving the boundaries of the means and standard deviations of system response. If the hybrid uncertainties in the system are treated as single uncertainty, the obtained results may be unreasonable.