The novel method to produce hydroxylated boron nitride（OH-BN）∶ the hexagonal boron nitride（h-BN）was exfoliated into nanosheets by NaOH-assisted physical ball milling with preliminary hydroxylation modification， and further hydroxylation modification was carried out in NaOH solution by hydrothermal method followed by acid washing and drying to obtain OH-BN. Using different diisocyanate and hydrophilic chain extenders，a variety of waterborne polyurethane（H-WPU）were synthesized，which，combined with OH-BN，was used to prepare hydroxylated hexagonal boron nitride（OH-BN/H-WPU）coatings. And hydroxylated hexagonal boron nitride thermal conductive polyurethane coating was prepared by screen printing method. The OH-BN was characterized by FT-IR，XRD，TEM，TGA，and the factors affecting the thermal conductivity OH-BN/H-WPU coating were investigated. The results showed that OH-BN was successfully hydroxylated and the typical hexagonal structure of h-BN was retained，and the dispersing performance in water and waterborne polyurethanes（H-WPU） was improved. When H-WPU synthesized with isophorone diisocyanate and 2，2-bis（hydroxymethyl）propionic acid was used，and the mass of OH-BN was 20% of H-WPU，the prepared OH-BN/H-WPU coating showed the best thermal conductivity of 0. 278 3 W/（m·K），which was 0. 077 3 W/（m·K）higher than that of the pure H-WPU coating.