The invention provides a water-based paint capable of shielding Wi-Fi signals as well as preparation and application methods thereof. The water-based paint is composed of the following components in parts by weight: 100 parts of water-based latex, 20-150 parts of nickel powder, 10-100 parts of conductive carbon black, 50-200 parts of deionized water, 3-15 parts of flatting agent, 2-10 parts of water-based conductive agent and 2-10 parts of dispersant. The preparation and application methods of the water-based pain comprise adding the dispersant, the nickel powder and the flatting agent to the water-based latex and stirring and dispersing by using a high-speed stirrer for 5-30 minutes firstly, next, adding the conductive carbon black, the deionized water and the water-based conductive agent to the slurry and dispersing to obtain the even water-based paint under the stirring of the high-speed stirrer, and then evenly applying the water-based paint to the surface of a substrate and drying. The water-based paint is pollution-free and capable of shielding Wi-Fi signals, has the advantages of good texture, wear resistance, scrawling prevention and the like, and can be widely applied to multiple fields.