The utility model relates to a rolling oil spray beam of a tandem hot rolling mill. The rolling oil spray beam comprises a spray beam pipe and a plurality of spray nozzles which are distributed on the spray beam pipe. The spray nozzles are arranged on spray nozzle carriers. The spray nozzle carriers are detachably installed on connecting holes which are arranged at the bottom end of the spray beam pipe. Each connecting hole is of the shape of a dovetail guide rail. Each spray nozzle carrier is of the shape of a dovetail groove which is matched with the dovetail guide rail. The spray nozzle carriers are connected onto the spray beam pipe in a socket-connecting way. Plugs are arranged at the two ends of the spray beam pipe. Since the spray nozzles are separately connected onto the spray beam pipe, compared with that the spray nozzle is a single hose and the hose is integrally connected with the spray beam pipe in the prior art, the rolling oil spray beam has the advantages that the spray nozzles can be conveniently disassembled at any time and the dredging or replacement of the spray nozzles is facilitated; and moreover, the plugs can be conveniently disassembled and the washing of the spray beam pipe is facilitated.