The invention provides casting coating for a spun cast pipe socket and a preparation method of the casting coating. The casting coating comprises, 54-59 parts of synthetic quartz, 3-6 parts of crystalline flake graphite, 4.3-4.6 parts of sodium bentonite, 0.34-0.47 part of polyvinyl alcohol, 0.32-0.44 part of aluminum dihydrogen phosphate, 0.18-0.32 part of sodium carboxymethylcellulose, 0.15-0.23part of surface active agents, 0.31-0.42 part of defoaming agents, and 31-34 parts of water. The preparation method comprises the following steps of (1) preparation of refractory powder; (2) preparation of accessories; (3) stirring: (4) preparation of the surface active agents and the defoaming agents; (5) adding of the surface active agents; (6) preparation of a finished product; and (7) use ofthe finished product. According to the casting coating for the spun cast pipe socket, the anti-sand burning effect is extremely good, the production cost is greatly reduced, and the production environment is improved.