During the braking process of the anti-lock braking system, when the electronic control device determines that a wheel tends to lock according to the wheel speed signal input by the wheel speed sensor, the ABS enters the anti-lock braking pressure adjustment process. For example, when the electronic control device determines that the right front wheel tends to be locked, the electronic control device energizes the liquid inlet solenoid valve that controls the brake pressure of the right front wheel, so that the right forward liquid solenoid valve turns into a closed state, and the brake master cylinder outputs If the brake fluid no longer enters the right front brake wheel cylinder, the electronic control device will power off both the right forward solenoid valve and the outlet solenoid valve, turn the inlet solenoid valve into the open state, and turn the outlet solenoid valve into the closed state. At the same time, the electric pump is energized to run, and the brake fluid is sent to the brake wheel cylinder. The brake fluid output by the brake master cylinder and the brake fluid pumped by the electric pump pass through the right forward fluid solenoid valve in the open state. Enter the right front brake wheel cylinder, so that the brake pressure of the right front brake wheel cylinder increases rapidly, and the right front wheel starts to decelerate again.