The invention discloses a counter-blower water seal device. The device is characterized by comprising a rapid connector, a bend, a connection flange, a casing pipe, a guide groove and a mill train end plate. The flange rolled piece inlet end of the connection plate stretches into a steel outlet hole of the mill train end plate and is in matched connection with the mill train end plate, the joint is sealed through a first seal ring, and the other end is in sleeved connection with the casing pipe. The guide groove penetrates through the casing pipe, and the rolled piece inlet end of the guide groove is matched with the flange rolled piece inlet end. The connection end face of the guide groove is in bolted connection with the casing pipe, the joint is sealed through a second seal ring, and the distance between the guide groove and the connection flange is adjusted by adjusting the second seal ring. The wall of the casing pipe is provided with a threaded through hole and connected with the bend through an inner connector. The bend and the rapid connector are connected through an inter connector. The counter-blower water seal device has the advantages that the structure is simple and compact, machining, installation and replacement of the guide groove which is prone to abrasion are convenient, the problems that mist at end plate outlets of a pre-precision rolling unit, a precise rolling unit and a reducing-sizing mill is large and a large amount of water is splashed around are solved trough simple cooperation of a small number of parts, and working environment is improved.