Cumulative cutting device for thick-wall metal pipe columns

The invention provides a cumulative cutting device for thick-wall metal pipe columns. The cumulative cutting device comprises an upper connector and a projectile tail, and a first annular cutting unit, a first perforating unit, an energy unit, a second perforating unit and a second annular cutting unit are coaxially and sequentially arranged between the upper connector and the projectile tail and from the upper connector to the projectile tail. By integration of the annular cutting units, the perforating units and the energy unit into one cumulative cutting device, synergistic effects of high penetrating power of the perforating units and large area of the annular cutting units are achieved, and by the energy unit which provides appropriate energy, effectiveness in cutting of the thick-wall metal pipe columns is achieved. Since the perforating units are close to the energy unit, energy of the energy unit can be well transmitted to penetration planes, on the thick-wall metal pipe columns, of the perforating units, and excellent cutting effects can be achieved.