The invention discloses an aqueous PU velvet resin used for synthetic leather, which comprises the following raw materials by weight percent: 40-50% of aqueous polyurethane resin, 40-50% of water, 2-5% of low-temperature sheep bar powder, 2-4% of silicon dioxide velvet powder, 1-3% of organic silicone oil smoothing agent, 1-4% of extinction powder, 0.5-1% of organic silicon flatting agent, 2-5% of organic silicon antifoaming agent and 0.5-2% of aqueous polyurethane thickening agent. The aqueous PU velvet resin used for synthetic leather of the invention takes water as solvent to replace toxic solvent, such as dimethyl fomamide, butanone and the like and has the advantages of being non-combustible, safe and environment-friendly, saving cost and the like. The aqueous PU velvet resin also has the advantages of good film-forming resistance, firm bonding, coating solvent resistance, cold resistance, hydrolysis resistance and heat-proof aging. Products fabricated by using the resin have the characteristics of plump feel, unique velvet effect, strong real leather quality, fine and smooth texture, good air permeability and the like.