The invention relates to a falling prevention device applied to a three-dimensional garage and the three-dimensional garage with the falling prevention device. The falling prevention device comprises a main frame with a containing cavity. A part of a locking hook is located in the containing cavity and fixedly connected with a first rotary shaft. The first rotary shaft is hinged to the main frame. The locking hook is provided with a groove and a protruding part. A part of a falling prevention hook is located in the containing cavity and fixedly connected with a second rotary shaft. The second rotary shaft is hinged to the main frame. One end of the second rotary shaft protrudes out of the main frame. The upper portion of the falling prevention hook abuts against the protruding part. One side of the main frame is provided with a first hanging and connecting piece. The second rotary shaft protruding out of the main frame is fixedly connected with a first reset piece. The first reset piece is connected with the first hanging and connecting piece through a first spring. A space for containing a vehicle carrying plate is defined by the locking hook and the falling prevention hook which are located outside the containing cavity. According to the falling prevention device, by designing the brand-new structure, the function of preventing the vehicle carrying plate from falling can be achieved through simple combination of parts.