For enamel coating, the pretreatment of metal substrate is one of the most important process.for steel enamel coating, the pretreatment of steel body has different requirement according to different types of steel plate. generally for enamel grade steel like dc01ek, dc04ek or dc06ek, there is only degreasing needed, to move out all the oils on the steel surface. In reasonable enamel coating process, enamel slurry should be coated on metal body with uniform thickness. it will make big difference to final product’s property. it will make big difference to final product’s property. Spray enamel coating in wet process spray enamel coating is to compress air to spray enamel slurry or powder to body metal. spray enamel coating in wet process is prevented first, then in the mid of 20th century, dry powder spray is prevented, it ’ s to use electrostatic adsorption to let enamel powder adhere on body metal. Enamel manufacturing process mainly include enamel frit manufacturing, metal body casting, enamel coating, drying, firing and testing. for art enamel, cookware, sanitary and architecture etcit will need decorating and packaging for its good appearance and daily use; for industrial enamel, it will need to be tested then assemble.