The invention discloses a WPU/PTFE composite hydrophobic coating and a preparation method thereof. The preparation method comprises the following steps that a silane coupling agent is added into PTFEemulsion and stirred; then, the PTFE emulsion added with the coupling agent is added into waterborne polyurethane and uniformly stirred to prepare coating emulsion; the surface of a to-be-coated matrix is evenly coated with the prepared coating emulsion and air-dried at room temperature, the matrix is placed into a heating box for drying after no emulsion drops, the matrix is cooled along with a furnace and then taken out, and the WPU/PTFE composite hydrophobic coating is prepared. The preparation process is simple, the cost is low, there are no strict requirements on basic materials, the coating is high in applicability, and the coating can be applied to surface corona prevention of a high-voltage line and can also be applied to water prevention on the surface of electrical equipment. Thecoating can be applied to the surfaces of anti-corrosion and hydrophobic materials, and especially has a relatively large application prospect on corona-resistant discharge of the surface of a powerline.