A bushing, comprising: a flow-guiding rod, wherein a cooling channel is provided in a rod portion of the flow-guiding rod, a coolant inlet pipe and a coolant outlet pipe are provided at end(s) of the flow-guiding rod, and the coolant inlet pipe and the coolant outlet pipe are communicated with the cooling channel; the flow-guiding rod is adapted to receive cooling water as coolant, the cooling channel is configured to be a water cooling channel, the coolant inlet pipe is configured to be a water inlet pipe, the coolant outlet pipe is configured to be a water outlet pipe, and the water inlet pipe and the water outlet pipe are connectable to a water cooling circulation loop of a converter valve tower; and the rod portion of the flow-guiding rod is of a tubular shape, and a tube wall of the rod portion is hollow; the water cooling channel is disposed inside the tube wall, which is hollow, of the rod portion; characterized in that: the tube wall is a triple-layer hollow tube wall, the triple-layer hollow tube wall includes a first-layer tube wall, a second-layer tube wall and a third-layer tube wall nested along a radial direction of the flow-guiding rod in sequence; a joint of the water inlet pipe configured to be jointed with the water cooling circulation loop of the converter valve tower and a joint of the water outlet pipe configured to be jointed with the water cooling circulation loop of the converter valve tower are located on a same end of the flow-guiding rod, and a grille or flow-guiding holes are formed in the second-layer tube wall at one end thereof away from the water inlet pipe or the water outlet pipe; the water cooling channel includes an outer annular water cooling channel disposed between the third-layer tube wall and the second-layer tube wall, and an inner annular water cooling channel disposed between the second-layer tube wall and the first-layer tube wall, the outer annular water cooling channel is communicated with the inner annular water cooling channel via the grille or the flow-guiding holes; the water inlet pipe is communicated with the outer annular water cooling channel, and the water outlet pipe is communicated with the inner annular water cooling channel; and the outer annular water cooling channel and the inner annular water cooling channel are isolated from a tube hole of the rod portion. a coolant inlet pipe and a coolant outlet pipe are provided at end(s) of the flow-guiding rod, and the coolant inlet pipe and the coolant outlet pipe are communicated with the cooling channel; the flow-guiding rod is adapted to receive cooling water as coolant, the cooling channel is configured to be a water cooling channel, the coolant inlet pipe is configured to be a water inlet pipe, the coolant outlet pipe is configured to be a water outlet pipe, and the water inlet pipe and the water outlet pipe are connectable to a water cooling circulation loop of a converter valve tower; and the rod portion of the flow-guiding rod is of a tubular shape, and a tube wall of the rod portion is hollow; the water cooling channel is disposed inside the tube wall, which is hollow, of the rod portion; characterized in that: the tube wall is a triple-layer hollow tube wall, the triple-layer hollow tube wall includes a first-layer tube wall, a second-layer tube wall and a third-layer tube wall nested along a radial direction of the flow-guiding rod in sequence; a joint of the water inlet pipe configured to be jointed with the water cooling circulation loop of the converter valve tower and a joint of the water outlet pipe configured to be jointed with the water cooling circulation loop of the converter valve tower are located on a same end of the flow-guiding rod, and a grille or flow-guiding holes are formed in the second-layer tube wall at one end thereof away from the water inlet pipe or the water outlet pipe; the water cooling channel includes an outer annular water cooling channel disposed between the third-layer tube wall and the second-layer tube wall, and an inner annular water cooling channel disposed between the second-layer tube wall and the first-layer tube wall, the outer annular water cooling channel is communicated with the inner annular water cooling channel via the grille or the flow-guiding holes; the water inlet pipe is communicated with the outer annular water cooling channel, and the water outlet pipe is communicated with the inner annular water cooling channel; and the outer annular water cooling channel and the inner annular water cooling channel are isolated from a tube hole of the rod portion.