Abstract: The turn-skipping of helical magnetic flux compression generators was analyzed, considering such factors as armature/stator eccentricity, non-uniform of armature surface and thickness, and detonation end effect, etc. Utilizing a more precise calculation model in which the space intersection curve of the expanding armature and the stator was taken into account, a more accurate formula of armature/stator eccentricity tolerance was developed and the conclusion is that the simplified calculation model is precise enough in practice to prevent the turn-skipping. Meanwhile, other factors such as the non-uniform of armature surface and thickness, and the detonation end effect which will also lead to the turn-skipping are also intensively analyzed and calculated. It is concluded that the length of