The invention belongs to water-proof air-permeable polyurethane synthetic leather in the technical field of synthetic leather, comprising the following components by weight percent: 60-70% of polyurethane particles, 3-7% of lubricant, 1-3% of foaming agent, 4-8% of reconcile resin, 10-15% of calcium carbonate, 10-15% of sodium chloride the grain diameter of which is 100-200 meshes, and 1-3% of pigment. The preparation method of the invention comprises the following steps: feeding the materials into a blender, and evenly mixing the raw materials; placing into a banbury mixer, heating, plastifying; placing into a two-roller machine, gelling, homogenizing, filtering by a filter and extruding; placing into a calender, and pulling out into rubber fabric; placing into a laminator, and fitting with base fabric and shell fabric at the condition of heating and pressurizing; and placing into a foaming machine, decomposing and foaming at the high temperature, cooking in water for 10-24 hours at the temperature of 50-60 DEG C, changing water for 2-5 times, knurling and postprocessing. The beneficial effects of the invention are as follows: sodium chloride is added and then removed in preparation process, more extremely fine holes are generated, and the air permeability of the synthetic leather of the invention is enhanced.