A fall arrest device includes a braking device, a frame, and a rotating member connected to the frame. The rotating member includes a main body and a plurality of pawls which are pivotally connected to a mounting portion of the main body. Each of the pawls has an abutting portion, a pivot, and a body portion. The braking device has a plurality of abutted portions. When a rotation speed of the rotating member is greater than or equal to a predetermined rotation speed, the abutting portions abut against the abutted portions to stop a rotation of the rotating member. When the rotation speed of the rotating member is smaller than the predetermined rotation speed, the body portion of each of the pawls touches a periphery of the abutted portions and swings as an outer diameter of the abutted portions of the braking device changes.