The invention relates to a device capable of realizing forced complete braking and manual resetting after a driver steps on an accelerator by mistake during emergency braking. The device consists of a recognizer for recognizing the situation that the driver steps on the accelerator by mistake during the emergency braking, a braking forced booster, a clutch forced booster and a system switch, wherein the recognizer for recognizing the situation that the driver steps on the accelerator by mistake during the emergency braking consists of an accelerator stroke spring and a switch for recognizing the situation that the driver steps on the accelerator by mistake; the brake forced booster (or the clutch forced booster ) consists of a booster and a checking lock; the booster consists of a boosting cavity, a boosting rod resetting spring, a boosting rod, a boosting blocking plate, a force-bearing blocking plate and a connecting rod; and the checking lock consists of checking teeth, a checking rod and a checking rod resetting spring. When the situation that the driver steps on the accelerator by mistake occurs, the switch for recognizing the situation that the driver steps on the accelerator by mistake during the emergency braking is closed, a brake and a clutch pedal are pushed to the bottom at the same time under the effect of the boosters, and the boosting rod is static at the tail end of the stroke by the checking lock, so that quick and safe braking of a motor vehicle is realized; and after the security is confirmed, the checking rod resetting switch is manually pressed for releasing the forced braking, and the motor vehicle enters a normal starting state.