An infiltration device for performing infiltration treatment on surface layers of magnets, characterized by comprising: a heating room having an annular groove and provided with a heating room opening end at a lower end; a rotary tray arranged below the heating room opening end; a rotary bracket installed on the rotary tray; a material box arranged on the rotary bracket; an elevating mechanism that enables the rotary tray to move upward and downward so that the rotary bracket and the material box enter the annular groove from the heating room opening end or exit the opening end from the annular groove; and a transmission device for enabling the rotary bracket to spin in the annular groove and revolve around a central axis of the rotary tray, wherein the rotary tray comprises: a tray temperature keeping member for keeping the temperatures of the heating room and the material box; and wherein the material box has a protrusion at the bottom, an upper cover of the material box has a recessed groove, and the protrusion of the material box and the recessed groove of the material box are arranged to fit with each other so that different material boxes are superimposed on each other in a concentric positioning manner, and wherein the rotary bracket has a recessed groove in the upper portion, and the recessed groove of the rotary bracket and the protrusion at the bottom of the material box are arranged to fit with each other so that the material box is placed on the rotary bracket in a concentric positioning manner, characterised in that a support member is provided below the tray temperature keeping member, and a cooling channel is provided inside the support member. a heating room having an annular groove and provided with a heating room opening end at a lower end; a rotary tray arranged below the heating room opening end; a rotary bracket installed on the rotary tray; a material box arranged on the rotary bracket; an elevating mechanism that enables the rotary tray to move upward and downward so that the rotary bracket and the material box enter the annular groove from the heating room opening end or exit the opening end from the annular groove; and a transmission device for enabling the rotary bracket to spin in the annular groove and revolve around a central axis of the rotary tray, wherein the rotary tray comprises: a tray temperature keeping member for keeping the temperatures of the heating room and the material box; and wherein the material box has a protrusion at the bottom, an upper cover of the material box has a recessed groove, and the protrusion of the material box and the recessed groove of the material box are arranged to fit with each other so that different material boxes are superimposed on each other in a concentric positioning manner, and wherein the rotary bracket has a recessed groove in the upper portion, and the recessed groove of the rotary bracket and the protrusion at the bottom of the material box are arranged to fit with each other so that the material box is placed on the rotary bracket in a concentric positioning manner, characterised in that a support member is provided below the tray temperature keeping member, and a cooling channel is provided inside the support member. a tray temperature keeping member for keeping the temperatures of the heating room and the material box; and wherein the material box has a protrusion at the bottom, an upper cover of the material box has a recessed groove, and the protrusion of the material box and the recessed groove of the material box are arranged to fit with each other so that different material boxes are superimposed on each other in a concentric positioning manner, and wherein the rotary bracket has a recessed groove in the upper portion, and the recessed groove of the rotary bracket and the protrusion at the bottom of the material box are arranged to fit with each other so that the material box is placed on the rotary bracket in a concentric positioning manner, characterised in that a support member is provided below the tray temperature keeping member, and a cooling channel is provided inside the support member.