The invention relates to the technical field of butterfly valves, in particular to a moving seat type triple eccentric butterfly valve which comprises a valve body, a lower valve shaft, a valve seat,a multi-layer sealing ring, a valve plate pressure plate, a valve plate, an upper valve shaft, a valve plate sealing ring and a filling mechanism; the lower valve shaft is installed at the lower partof the valve body through a short shaft sleeve, is fixed through a back plug cover in a sealing manner and is connected with the lower part of the valve plate; the multi-layer sealing ring is circumferentially arranged on one side of the valve plate; the valve plate sealing ring is arranged between the multi-layer sealing ring and the valve plate; the valve plate pressure plate compresses and fixes the multi-layer sealing ring; the valve seat is a moving valve seat, is fixed on the valve body by using bolts and is matched with the multi-layer sealing ring; the upper part of the valve plate isconnected with the valve shaft; and the filling mechanism is installed between the valve body and the upper valve shaft. By adopting the device, the valve seat can be changed in the field, and the purpose that the valve seat is changed in a state that the valve is not disassembled from a pipeline can be achieved by adopting a large-diameter valve.