Nowadays,the brake engineers are challenged with brake pedal feeling optimization for customer satisfaction.To fulfil the target,a parametric model of the vacuum booster,i.e.the most important brake component,is a usefull aid.This paper introduced a dynamic modelling method of vacuum booster with Amesim.The model is constructed based on the internal subcomponents working mechanism,with the corresponding parameters obtained through measurements and bench tests.The characteristic curve of the calibrated model shows excellent agreement with the bench test results.The paper also provides two model application cases to adjust the structural parameters for brake pedal feeling improvement.The Amesim vacuum booster model can be viewed as a virtual prototype for further model adjustment and optimization.