The invention discloses a large-particle-size material dredging method. Firstly, a simulation test is carried out on an actual dredging working process; constructing a dredging system calculation model according to the parameters collected in the multiple test processes; the on-way attenuation law of slag conveying power under the condition of different slag conveying distances is fully reflected;the dredger pneumatic output power and the relation between the control index production effects of the pneumatic output power of the dredger are applied to actual dredging work of large-particle-size materials of a river channel, dredging relevant parameters are scientifically and reasonably set through a dredging system calculation model, and the dredging efficiency and effect of the large-particle-size materials are effectively improved.