The invention discloses an online detonator explosion preventing film-covering machine comprising a remote control table, a box-feeding conveyor and a main rack. The box-feeding conveyor is arranged on the right side of the main rack, the box-feeding conveyor and the main rack are located in the same direction and detachably connected through bolts; a film feeding mechanism is mounted on the mainrack, and a film taking-down mechanism is arranged on the lower side of the film feeding mechanism; a film wrapping mechanism is arranged on the left side of the film taking-down mechanism, and a horizontal seal folding mechanism is arranged on the upper side of the film wrapping mechanism; and the film feeding mechanism, the film taking-down mechanism, the film wrapping mechanism and the horizontal seal folding mechanism are fixedly connected with the main rack through bolts detachably. A traditional film-covering technique is changed, the requirements for the equipment temperature, the electromagnetic environment and other requirements in the aspect of safety during electric detonator production are met, the effect of automatic film-covering damp proofing is achieved, and the online detonator explosion preventing film-covering machine is high in production efficiency, safe, reliable and capable of automatically completing automatic film sealing of an outer covering film of a detonator packaging box.