The invention discloses a preparation method of PTFE (Polytetrafluoroethylene) copper clad laminate. The method comprises the following steps: 1, uniformly mixing raw material components of ceramic powder, silane coupling agents, deionized water and PTFE emulsion to form a PTFE glue solution; 2, soaking glass fiber cloth in the PTFE glue solution at a constant speed, and drying to obtain pretreated cloth; 3, superimposing the obtained pretreated cloth and a fluorine resin membrane into a raw substrate with specified thickness, covering the two sides of the raw substrate with copper foil, thenperforming sintering, maintaining pressure and then cooling to room temperature to prepare the PTFE copper clad laminate. The preparation method disclosed by the invention is simple, easy to operate,good in filler dispersion effect, uniform in mixing and good in product size stability. Through reasonable proportion, the prepared PTFE copper clad laminate has different dielectric constants within2.6-8.6 MHz; the dielectric loss factor is smaller than or equal to 0.003; the peeling strength is greater than or equal to 2.2 kN/m, and the comprehensive property meets use requirements and industrialized mass production requirements.