A method for preparing a charging plan for rock cavern excavation, in which plan drill hole locations for a round to be drilled in a tunnel face are determined in a predetermined coordinate system by using a drilling plan created by means of a computer-assisted design program. The method determines pull-out of a round on the basis of the locations of the hole ends and the topography of the rock remaining after a round blast, and designs or modifies a charging plan for a subsequent round on the basis of the thus determined pull-out.