The invention relates to a water-based UV-Monocoat colored coating for a plastic base material and a construction process. The water-based UV-Monocoat colored coating is prepared from water-based UV resin, aluminum paste, color concentrate or color paste, pearl powder, a solvent, an auxiliary agent, a photoinitiator and water. The water-based UV resin is 8-functional-group sulfonate anionic epoxy modified polyurethane acrylate; according to the water-based UV-Monocoat for the plastic base material, a paint film of the water-based UV-Monocoat is high in metal feeling, and the water-based UV-Monocoat has excellent adhesive force, wear resistance, alcohol resistance, boiling resistance, flexibility, scratch resistance, hand perspiration resistance, humidity and heat resistance, pollution resistance and skin feeling; the recoatability is not influenced, and moreover, the construction is convenient, safe and environment-friendly. The coating can be used for 3C products such as plastic base materials such as ABS, PC, ABS+PC, ABS+glass fibers and PC+glass fibers, such as stylus televisions, mice, keys, mobile phones, household appliances, switches, packaging materials and automotive upholstery, and can also be used for surface coating of various metal alloy primers.