The invention provides a production process of colorfully-painted and back-engraved crystal glass. The production process is realized by sequential steps of prefabricating a colorfully-painted pattern mould, mixing and agitating, drying material powder, granulating, heating and fusing, dropping materials into the mould, cooling and de-molding, annealing, carrying out cold machining and the like. According to the production process, a laser precision engraving machine is used for engraving patterns on a metal mould; then fused glass liquid is processed by the process of dropping the materials into the mould, cooling and de-molding, and annealing to obtain a semi-finished product; and then, the cold machining is carried out and manners of back engraving, circular engraving, floating engraving and the like are utilized to machine back loss of a product and fuzzy pattern details in a previous production process to enable to the patterns to be vivid. When paint is used for gradually coloring the product layer by layer, an outer layer needs to be colored under the precondition that the inner layer is completely dried. After the coloring is finished, the product is dried to guarantee the durability of colorfully-painted colors. Compared with an existing product, the product prepared by the production process disclosed by the invention has the characteristics of long preservation time, bright pattern colors and capability of vividly presenting three-dimensional patterns.