The invention discloses UV-curable polyurethane acrylate photosensitive resin and its preparation method and use. The preparation method of the photosensitive resin comprises that cardanol is modified to form cardanol etherified diol, the cardanol etherified diol and diisocyanate undergo a reaction so that the cardanol is terminated and polyurethane is prepared, the unsaturated double-bond group of the polyurethane molecule is epoxidized, and the epoxidized group and (methyl) acrylic acid undergo a reaction to produce the UV-curable polyurethane acrylate photosensitive resin. The preparation method is novel, is simple and is easy to control. The product has adjustable viscosity and has high active group content. Through use of the cardanol group in the UV-curable polyurethane acrylate photosensitive resin, the hydrophobicity and chemical agent resistance of the photosensitive resin are improved and the flexibility of the cured body after curing is improved. The photosensitive resin can be used in the fields of UV cured coatings, ink and adhesives.