To extend the service life of cutting tool, AlCrBN/AlCrSiN nanocrystalline multilayer composite coating with high hardness, high wear resistance, self-lubrication and high thermal stability was prepared on the cemented WC-Co carbide and stainless steel substrate by multi-arc ion plating technology. The morphology, structure, mechanical properties and wear resistance of the coating before and after annealing in the range of 600~1000 ℃ were systematically studied by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, nano-indentation and friction and wear tester. The AlCrSiN/AlCrBN coating exhibits a typical nanocrystalline composite multilayer structure with fcc-AlCrN nanocrystals embedded in the amorphous SiNx and BNx. The coating has excellent thermal stability performance, and its structure can be maintained to 800 ℃ without change. When the temperature increases to 900 ℃, the coating undergoes amplitude modulation decomposition, forming structures such as c-AlN, hcp-AlN and Cr2N. The structure of coating is stable after annealing at 1000 ℃, since CrN phase also can be detected in the coating. The coating nanohardness and average friction coefficient are 29.15 GPa and 0.67, respectively. AlCrSiN/AlCrBN coating has excellent mechanical properties, wear resistance and high temperature thermal stability, remains stable below 800 ℃, and can still maintain high hardness and good wear resistance after annealing at 1000 ℃, and has good application prospects in the field of high-speed cutting tool coating.