▎ 摘　　要

A hydrodynamic model, which discards potential notation but couples with the full Maxwell's equations and boundary conditions, was proposed. The method took into account magnetic field but ascertained the type of surface plasmon-polaritons in the monolayer graphene. Utilizing the method, we investigated the spectrum of surface plasmon-polariton with or without the external magnetic field and found that the plasmon-polariton spectrum was suppressed compared with the traditional method. In the infrared and ultraviolet region, the fluence of external magnetic field can be ignored. There was an uplift in the transition region, which is roughly around q0 similar to 1, which is attributed to the external magnetic field. Finally, the surface plasmon-polariton spec-trum in the ultraviolet region was dominated by the nonlocal effect.