Abstract: A superjunction LDMOS and its manufacturing method are disclosed. The superjunction LDMOS includes a diffused well in which a superjunction structure is formed; the superjunction structure has a depth less than the depth of the diffused well. The manufacturing method includes: provide a semiconductor substrate; form a diffused well in the semiconductor substrate by photolithography and high temperature diffusion; form an STI layer above the diffused well; form a superjunction structure in the diffused well by ion implantation, wherein the superjunction structure has a depth less than the depth of the diffused well; and form the other components of the superjunction LDMOS by subsequent conventional CMOS processes. The method is compatible with conventional CMOS processes and do not require high-cost and complicated special processes.