The invention discloses a safety valve clack magnetic fluid grinding polisher and a safety valve clack magnetic fluid grinding polishing method. The safety valve clack magnetic fluid grinding polisher comprises a first mounting mechanism used for mounting a safety valve clack and a second mounting mechanism used for containing magnetic fluid grinding materials. The first mounting mechanism can drive the safety valve clack to selectively enter the second mounting mechanism, the safety valve clack and the magnetic fluid grinding materials in the second mounting mechanism are in contact and make relative movement to achieve grinding and polishing of the safety valve clack. The second mounting mechanism further comprises a magnetic field generating device which can selectively make magnetic fluid materials to be in cohesion, so that grinding and polishing of the safety valve clack are conducted under the cohesion state of the magnetic fluid grinding materials. Through the magnetic fluid grinding polisher, the grinding materials are discarded into magnetic fluid by the flexible effect of the magnetic fluid; grinding and polishing are controlled through an external magnetic field so that the safety valve clack can be evenly subjected to the external force effect; and accordingly, grinding and polishing repair is achieved.