The invention discloses a deep-hole screw locking machine and an application method thereof and belongs to the technical field of screw locking machines. The deep-hole screw locking machine comprisesa rack. The rack is provided with a transverse movement mechanism and a transverse driving motor. The transverse movement mechanism is provided with a longitudinal movement mechanism and a longitudinal driving motor. An ascending-and-descending mechanism is mounted at the front end of the longitudinal movement mechanism and provided with a screw machine. The screw machine comprises a left clampingpiece, a right clamping piece and a screwdriver. An iron core is connected to the lower end of the screwdriver in a sliding manner. A stop block is fixedly connected to the position, above the iron ore, of the screwdriver. A sliding block is connected to the screwdriver in a sliding manner. A jacking rod is connected between the sliding block and the iron core in a sliding manner. A spring is connected between the sliding block and the stop block. A first conducting ring and a second conducting ring are connected to the screwdriver. A first joint is connected to the first conducting ring, anda second joint is connected to the second conducting ring. By means of the deep-hole screw locking machine and the application method thereof, a screw can be precisely locked, and the probability ofscrew shifting or falling is lowered.