UV-curing method is used to solidify the phosphor in the process of LED packing, the influence of UV curing time on the optical properties of LED is studied. Nine different kinds of curing time is determined in the experiment of LED packing, after packaged, test the physical character of LEDs and then select the fully cured samples to conduct aging test experiments with constant current and test their photometric &colorimetric parameters regularly. The experimental results show that the adhesive is nearly cured when the curing time is greater than 120 s, the maximum and minimum average wavelength, color temperature and color rendering index of the LEDs for different testing time have a difference of almost 1.2 nm, 200 K, 1.3 respectively for different kinds of curing time, the luminous flux decay rate is higher than others when the curing time is longer than 210 s. So, the suitable curingtime for this kind of UV radiation curing adhesive is 120~180 s under the UV power density of 106.6 mW/cm2. Studying the influence of curing time on properties of LED by optical method is instructive and meaningful to use UV curing coatings in the process of LED packing.