An escape device for high-rise buildings includes an escape capsule, a speedup gear mounted to the escape capsule, a track provided with a rack with which the speedup gear is engaged so that the escape capsule can move along the track, and a damper including a rotor. The speedup gear in operation drives the rotor into rotation and the damper is capable of converting a portion of kinetic energy of the escape capsule to the electric energy. The escape device can be braked at any position at a building.