The invention discloses a die bonding material for LED encapsulation and a preparation method thereof. The die bonding material comprises tin-based soldering powder, high-thermal-conductivity particles and die-bonding solder paste, wherein the high-thermal-conductivity particles include one or two substances selected from diamond particles, carbon nanotubes and SiC, and the volume of the high-thermal-conductivity particles accounts for 0.1-70% of the total volume of the tin-based soldering powder and the high-thermal-conductivity particles. As the die bonding material of the invention contains the high-thermal-conductivity particles, high thermal conductivity can be achieved on the premise of meeting the bonding strength between an LED chip and a heat sink and not affecting the electrical performance, and the thermal conductivity is several times or even dozens of times that of the existing LED die bonding solder. By adopting the die bonding material of the invention, the thermal resistance of power LED devices is reduced effectively, the heat dissipation capacity of LED chips is improved, the junction temperature of LED chips is reduced, and the service life of LED devices and application products is increased.