The Fuzzy control method in an automobile Electronic Control Braking System (ECBS) on varying pavement is studied. According to the characteristics of an automobile ECBS which adapts to the varying pavement, the ECBS fuzzy control system is established. The ECBS fuzzy controller based on slip is designed. When the automobile is braking on uniform pavement and varying pavement, the computer simulation is fulfilled for the deceleration threshold value control and the slip fuzzy control of the automobile ECBS by using MATLAB/Simulink. The results show that the automobile ECBS using fuzzy control can obtain better fundamental braking performance on varying pavement, wheel locking doesn’t appear, both braking distance and braking time are short, the fluctuation of the wheel periphery velocity is little and smooth, its braking performance is obviously better than the deceleration threshold value control.