In this paper, analysis methods for brake squeal including substructure modal composition analysis and substructure modal parameters sensitivity analysis are presented. These methods are based on a new closed-loop coupling disc brake model, where the coupled nodal pairs in each coupling interface are connected tightly. This assumption is different from other existing models in literatures, where the interface nodes are coupled through assumed springs. Based on this new model, two analysis methods are derived: Substructure modal composition analysis indicates the contribution of modes of each substructure to the noise mode; Substructure modal parameters sensitivity analysis indicates the sensitivity of the real part of system’s eigenvalue to component’s modal frequency and shape. Finally, the presented analysis methods are applied to analyse a high frequency squeal problem of a squealing disc brake. It is found that the complex eigenvalue analysis results are correlated well with those from squeal test. Results of substructure modal composition analysis and sensitivity analysis are compared to those from literatures. The influence of substructure modal parameters on system instability is investigated and the key structural factors that affect the squeal occurrence most are found. The results correspond qualitatively with those from the traditional analysis methods.