The invention discloses a white-light LED encapsulation device and a preparation method thereof. The device comprises a carrier and an LED blue-light chip arranged on the carrier; the LED blue-light chip is covered with a quantum dot particle and fluorescent powder mixed glue layer; quantum dot particles, fluorescent powder and a transparent gel material are mixed and are applied onto the LED blue-light chip, so that the quantum dot particle and fluorescent powder mixed glue layer can be formed; the quantum dot particles are composed of quantum dots, a mesoporous material and a water-resisting and oxygen-blocking material; the quantum dots are distributed in the mesoporous material; and gaps between the quantum dots and the mesoporous material are filled with the water-resisting and oxygen-blocking material. According to the white-light LED encapsulation device and the preparation method thereof of the invention, the quantum dot particles and the fluorescent powder are mixed and are dispersed in the transparent gel material, and an obtained mixture is directly applied onto the LED blue-light chip, so that chip direct contact type encapsulation is carried out, and the luminous efficiency of an LED can be greatly improved; the quantum dot particles are used for direct LED blue-light chip contact type encapsulation, so that the white-light LED device can be obtained; the R9 value of the white-light LED device is far higher than that of a conventional white-light LED device; and the white-light LED device of the invention completely expresses a saturated and wide-gamut color, and not only is the color of the white-light LED device is bright, but also the brightness and energy efficiency of the white-light LED device are significantly improved.