In order to study the brake squeal issue of an SUV disc brake, a complete finite element model (FEM) for contact coupling of disc brake is established by using finite element software. The validity of the FEM is verified by the experimental modal analysis method. The complex eigenvalue analysis method is adopted to predict the instable mode of the system. The influence of friction coefficient, brake rotation speed, brake pressure and disc stiffness on brake squeal is further analyzed. The analysis results indicate that: (1) the influence of friction coefficient on the brake squeal is large, and the brake squeal tendency rises with the increase of the friction coefficient; (2) the brake rotation speed has little influence on the brake squeal; (3) the brake pressure has a certain influence on the brake squeal, and the brake squeal decreases with the increase of brake pressure; (4) the disc stiffness also exists some influence on the brake squeal, but the relationship between them is complicated.