The present invention relates to a method for producing a tower segment of a concrete tower of a wind energy installation, comprising the steps: providing a segment mold (2) having at least one formwork (1) for defining a mold of the tower segment (80) that is to be produced and for filling with concrete; filling the segment mold (2) with concrete in order to form the tower segment (80) by the subsequent hardening of the concrete; measuring the tower segment (80) thus hardened for creating a three-dimensional, virtual actual model of said tower segment (80); producing said three-dimensional actual model; comparing the three-dimensional actual model with a predefined mold, in particular a stored three-dimensional, virtual target model; and determining a deviation between both virtual models and changing the segment mold (2), in particular changing the at least one formwork (1) when the deviation exceeds a first predefined threshold value.