Compared with traditional VDMOS, the superjunction and high k dielectric structure VDMOS could achieve higher breakdown voltage and lower on-resistance. The effects of various structural parameters on electric field distribution, breakdown voltage and specific on-resistance of 3D cylindrical high k VDMOS with and without interfacial charges were systematically summarized by simulation software. The variation trend and reason of breakdown voltage and specific on-resistance with parameters were studied and qualitatively analyzed. This study provided a reference for the design of high k VDMOS.