Abstract: Hybrid materials composed of Sn nano particles deposited on BN surface (BN-Sn NPs) were constructed as thermal conductive and electrical insulating fillers for epoxy(EP) by liquid-phase chemical reduction method. The diameter and melting point of Sn nano particles on BN-Sn NPs surface are 10–30 nm and 166.5–195.3℃, respectively. Both the Zeta potential of BN-Sn NPs powder and thermal conductivity of BN-Sn NPs pressed sheet increase, while the contact angle of EP droped on BN-Sn NPs pressed sheet decreases after BN surface deposited with nano Sn. During the curing process of BN-Sn NPs/EP composites, the nano Sn particles on BN-Sn NPs surface melt and sinter, simultaneously bridge the individual fillers, which results in the lower thermal contact resistance between the fillers, and the improved interfacial behavior. The feature of enhanced thermal conductivity reflects in BN-Sn NPs/EP composites. When the filler volume fraction is 30vol%, the thermal conductivity of BN-Sn NPs/EP composites reaches 1.61 W(m·K)⁻¹, nearly 50% higher than that of the pristine BN/EP composites (1.08 W(m·K)⁻¹). The results of Monte Carlo simulation demonstrate that the thermal contact resistance (R_c) of BN and BN-Sn NPs in the EP matrix are 6.1×10⁶ K·W⁻¹ and 3.7×10⁶ K·W⁻¹, respectively. The BN-Sn NPs/EP composites exhibit higher dielectric loss and lower dielectric strength and volume resistivity than that of the pristine BN/EP composites, while still have good electrical insulating properties.