3D semiconductor crystals are ideal to manipulate electronic devices. Therefore, how to prepare 3D semiconductor crystals is interesting. Here, we firstly report a facile and general route to 3D PANI nanoflowers self-assembed by nanoplates. A set of doping control experiments are carried out to find out the key factor in determining conductivity. At proper doping level of CSA, XRD patterns indicate PANI-CSA nanoplates crystallized well. HRTEM images further indicate these nanoplates are single crystals, which self assemble into nanoflowers. Interestingly, these nanoflowers have the highest conductivity due to the highest crystallinity and proper doping level. Thus, it can be concluded that crystallinity and doping level are two important factors influencing the conductivity. The novel method will be readily scalable to produce bulk quantities of PANI single crystals.