Provided is a method of producing a wet master batch, including the step of: solid-liquid separating and dehydrating a coagulum slurry obtained by mixing a rubber latex with a carbon black slurry containing a carbon black dispersed in water and coagulating the mixture, the solid-liquid separating and dehydrating step including gravity filtering and vacuum filtering the coagulum slurry on a filtration filter and then pressurizing, by means of a pressurizer, the coagulum slurry on the outer peripheral surface of a drum, to thereby pressure dehydrate the coagulum slurry. Also provided is a solid-liquid separating and dehydrating apparatus for wet master batch production, which includes: a filtration filter; a filtration portion; a drum; and a pressurizer.