"湿磨法" can be translated as "wet grinding method" or "wet milling process" in English, depending on the specific context and the level of technicality required.
"Wet grinding method" emphasizes the process of grinding in a wet environment.
"Wet milling process" is more commonly used in industrial contexts, especially when referring to the processing of materials like ceramics, minerals, or food products, where the material is milled in the presence of a liquid medium.