The invention discloses a preparing method of a hot stamping forming die insert with a shape follow-up cooling water way. The method comprises following steps that a, the lower half part shape of theshape follow-up cooling water way is machined on a common steel forging or steel casting base body; b, the machined pipeline corresponding to the shape follow-up cooling water way in shape is placed on the lower half portion shape in the step a; c, arc additive manufacturing of transition layer materials is carried out on an insert base body and the pipeline surface; d, secondary arc additive manufacturing of the high-temperature-wear-resisting strengthened layer material is carried out on the transition layer; e, the mold insert obtained after arc additive manufacturing is subject to slow cooling treatment after tempering; f, the mold insert obtained after cooling is subject to mechanical machining, and the mold surface shape and size precision meets the requirement. The problem that theshape follow-up cooling water way is hard to machine is solved, the service life of the mold is prolonged, the mold cooling efficiency is improved, and the mold manufacturing cost is reduced.