The invention belongs to the technical field of bolt and nut locking, and relates to a bolt and nut locking device. The bolt comprises a bolt head, a bolt column, a nut, a flat
washer and a
saddle-shaped elastic
washer, the bolt head is connected to one end of the bolt column. The nut is in threaded connection with the bolt column. A slot is formed in the flat
washer, and one side of the
saddle-shaped elastic washer is matched with the slot in an inserting manner; and after one side of the
saddle-shaped elastic washer is inserted into the slot, the flat washer and the saddle-shaped elastic washer form a V shape. Compared with a traditional method that a nut is screwed to a bolt head in a long
stroke to prevent scattering, the device has the advantages that the flat washer and the saddle-shaped elastic washer are designed to be of the V-shaped structure capable of being combined in an inserted mode, so that the nut only needs to be screwed into a short
stroke, enough elastic deformation and
friction force can be generated by extruding the saddle-shaped elastic washer, and the temporary locking state is achieved. The process is labor-saving and quick to operate. During formal installation, additional complex operation is not needed, the
workload of
assembly workers is reduced on the whole, and the working efficiency is improved.