Abstract: Wrinkling defects are prone to occur during the roll preforming process of aerospace composite Z-frames, which impairs the forming quality of the components. To address this issue, a finite element model for the roll preforming of aerospace composite Z-frames was established based on Abaqus, and the accuracy of the model was verified through process experiments. On this basis, a wrinkle amplitude evaluation index Δw was constructed by introducing the nodal rotational degree of freedom (UR), realizing the quantitative characterization of wrinkling defects. Using this evaluation method, the influences of roll gap, rolling speed and rolling load on the wrinkle evolution behavior were systematically investigated. The results show that wrinkling defects are mainly concentrated in the inner flange region. All three process parameters exert significant effects on the preforming quality, and each parameter has a reasonable value range. The minimum wrinkle amplitude and the optimal forming quality of the preform are obtained when the roll gap is 105% of the prepreg thickness, the rolling speed is 0.03 rad/min, and the rolling load is 0.3 MPa. The research confirms that the established finite element model and wrinkle evaluation method can effectively predict the evolution law of wrinkling defects during roll preforming, and can provide a reference for the process design and parameter optimization of roll preforming for aerospace composite frame components with complex cross-sections.