The invention relates to 2-functionality-degree polycaprolactone urethane acrylate and a preparation method and application thereof, and discloses low-viscosity 2-functionality-degree polycaprolactone urethane acrylate. The preparation method comprises the step that polycaprolactone glycol and isocyanate ethyl acrylate react to prepare 2-functionality-degree polycaprolactone urethane acrylate. The invention further discloses application of 2-functionality-degree polycaprolactone urethane acrylate to preparation of UV coatings or ink or adhesives. Isocyanate ethyl acrylate is adopted for preparing polycaprolactone urethane acrylate, the reaction process is simple and easy to control, the situation that gel is generated due to side reactions is not likely to happen, the polycaprolactone urethane acrylate product is low in viscosity and is beneficial to construction and application to UV formula products, when polycaprolactone urethane acrylate is used for UV spraying, no solvent or little solvent is added, and the requirement for application to the low-viscosity coatings is met. After low-viscosity 2-functionality-degree UV photocuring polycaprolactone urethane acrylate is cured, the excellent performance of good flexibility, good toughness, heat resistance, weather fastness and the like is achieved, and 2-functionality-degree polycaprolactone urethane acrylate can be applied as a raw material of the UV coatings, the ink and the adhesives.