[Purposes] The paper aims to study the influence of gradient magnetic field on natural convection heat dissipation of the vertical plate, which provides a new method to strengthen convection heat dissipation of the vertical plate. [Methods] The mathematical model of magnetically induced natural convection was constructed and the corresponding finite element program was written. The heat transfer law of magnetic field strengthening natural convection of the vertical plate under different magnet remanent flux density, different magnet position were analyzed. The heat transfer characteristics of the vertical plate with or without gradient magnetic field were compared. [Findings] When the magnet remanent flux density Br>1 T, the convective heat transfer capacity of the vertical plate increases with the increasing of the magnet remanent flux density of the magnet. When the magnet is located at the bottom of the vertical plate, it has the greatest influence on natural convection heat dissipation. The convective heat dissipation capacity of the vertical plate with two groups of magnets is stronger than that with single group of magnets. [Conclusions] The natural convection heat dissipation of the vertical plate can be strengthened or controlled by applying magnetic field.