Due to the inherent structural characteristics of MPVs (Multi-Purpose Vehicles), including a higher center of gravity, larger self-weight, and smaller wheel dimensions, the size of the brakes is constrained, resulting in diminished thermal capacity. Furthermore, in order to meet fuel economy and endurance mileage requirements, a lower drag coefficient is achieved through more aerodynamic structures, such as the wheel rim with small opening ratio, closed underbody shield including the air dam. However, these features lead to more brake cooling problem for MPVs, affecting the safety of driving. In this paper, a multi-time scale fluid–structure interaction simulation method is used to simulate the brake cooling time, with the accuracy of over 95%. This study found that the cooling time of brake disc is strongly correlated with the air throwing efficiency of the brake disc ventilation ribs, indicating that higher flow rate results in faster brake cooling. Based on this finding, the influence of the wheel rims, the brake shields, and the air dams on the braking cooling time was accurately evaluated. Closed wheel rim can increase the brake cooling time by 15.2%. By removing the air dams and opening holes at the root of the brake shields, the brake cooling time can be reduced by a total of 34.7%. For MPVs, the closed wheel rims have a little contribution to reducing the drag coefficient, while removing the air dams has a great influence on the drag coefficient, and opening holes at the root of the brake shields has almost no effect on the drag coefficient. This research provides a basis for the brake cooling design of MPVs.