Provided is a formation method of a semiconductor structure, including: providing a substrate having a first region and a second region, a plurality of discrete through holes being formed in the substrate, an arrangement density of the through holes in the first region being greater than that in the second region; forming a sacrificial layer filling the through holes; etching some thickness of the substrate around the sacrificial layer to form openings, the openings surrounding the sacrificial layer, a depth of the opening being less than a depth of the through hole in a direction perpendicular to a surface of the substrate; and removing the sacrificial layer, the openings communicating with the corresponding through holes to form trenches.