The invention discloses a catalyst heavy metal cycle pollution ageing reactor. The catalyst heavy metal cycle pollution ageing reactor comprises a reactor main body, a catalyst loading and unloading port, a feeding pipe, a gas outlet pipe, a grid, a spherical surface type tower plate and a gas inlet pipe; the reactor is divided into a settling section, an ageing section and a pre-distribution section from top to bottom; the cross sectional area of the reactor main body is shrunk from top to bottom; the grid is horizontally arranged at the ageing section of the reactor; the spherical surface type tower plate is arranged between the grid and the bottom end of the reactor; the feeding pipe passes through the upper part of the reactor and the grid and runs through the reactor to be positioned between the grid and the spherical surface type tower plate; the gas inlet pipe is arranged at the bottom of the reactor. The catalyst heavy metal cycle pollution ageing reactor provided by the invention is simple in structure, can flexibly switch hydrothermal ageing and heavy metal cycle pollution ageing, is simple in a cooling system, particularly adapts to requirements of high reaction temperature, large water vapor amount and long treatment time of cycle pollution ageing treatment, and can simulate the performance of an industrial balancing agent.