The invention belongs to the technical field of smelting of non-ferrous metals and specifically discloses an electrolytic bath and a preparation method thereof. The electrolytic bath is prepared by mixing and stirring quartz sand, quartz powder, vinyl ester resin, cobalt naphthenate and methyl ethyl ketone peroxide, which are extracted according to the proportion, then injecting a stirred object into a set electrolytic bath mold, molding and demolding. The electrolytic bath has not only higher compressive strength and flexural strength and high shearing strength, but also the characteristics of low energy consumption, small deformation and safety in use during the use, and can be widely used in the electrolysis process of smelting of the non-ferrous metals.