A fabrication method of a power semiconductor device is provided. Firstly, a plurality of trenched gate structures is formed in the base. Then, a body mask is used for forming a pattern layer on the base. The pattern layer has at least a first open and a second open for forming at least a body region and a heavily doped region in the base respectively. Then, a shielding structure is formed on the base to fill the second open and line at least a sidewall of the first open. Next, a plurality of source doped regions is formed in the body region by using the pattern layer and the shielding structure as the mask. Then, an interlayer dielectric layer is formed on the base and a plurality of source contact windows is formed therein to expose the source doped regions.