The invention discloses a straddling type mono-rail bogie without a primary spring. The straddling type mono-rail bogie comprises a frame and further comprises a traction device, a basic braking device, a vibration reducing device, a gear case, stabilizing wheels, guiding wheels and walking wheels, and the traction device, the basic braking device, the vibration reducing device, the gear case, the stabilizing wheels, the guiding wheels and the walking wheels are arranged on the frame. A traction motor longitudinally arranged and the gear case are directly hung on the outer side of the frame in a rigidity manner. An output shaft of the gear case is connected with an axle through a split coupling. The frame is provided with a split type shaft box composed of an upper shaft box body and a lower shaft box body. The upper shaft box body and the lower shaft box body are detachably and fixedly connected. The upper shaft box body is fixed to the frame and used for installing the basic braking device. Wheel replacing is achieved without vehicle erecting, and daily maintaining work of a vehicle is greatly improved.