The utility model relates to a braking device can include: the master cylinder, it includes main piston and the master cylinder body, the main piston moves with the footboard together, the master cylinder body make the main piston movably insert wherein and contain change its hydraulic fluid when making main piston motion, footboard power produces the piece, and it holds in the master cylinder body to the motion of main piston is limited when interfering with the main piston according to the motion of main piston, the braking actuator, its structure is for producing hydraulic pressure, the actuator connecting piece makes the braking actuator be connected to the stopper of installing on the wheel, and main connecting piece, make the master cylinder be connected to the actuator connecting piece. Consequently, can improve system dynamic response speed in emergency. The utility model discloses can realize the braking device of reduced size, use part quantity and cost through simple structure.