The invention discloses a water cooling shell of a mold liquid level detection sensor. An inner barrel blocking plate is connected to one end of an inner barrel in a sealing mode, a front cover is fixedly connected to the end, far away from the inner barrel blocking plate, of the inner barrel, and a cable connection groove is formed in the end, far away from the inner barrel blocking plate, of thefront cover; an outer barrel with the L-shaped cross section is fixedly arranged on the outer side wall of the inner barrel in a sleeving mode, the outer barrel is connected to the outer side wall ofthe inner barrel in a sealed mode through a blocking plate, and a cooling channel is formed between the inner barrel and the outer barrel through the blocking plate; and water nozzles are symmetrically connected to the barrel wall of the outer barrel, flanges are symmetrically and fixedly connected to the barrel wall of the end, close to the inner barrel blocking plate, of the outer barrel, and the cambered surfaces of the two flanges face downwards. According to the water cooling shell, it is guaranteed that the temperature of components in the shell is constant, impurities on the two sidesof each filter plate can be conveniently removed, and cleaning of filter screens is guaranteed.