The large-scale assembly and fabrication method for single-walled carbon nanotube (SWCNT) nano devices was implemented. Assembly of SWCNT field effect transistor (FET) was realized by floating potential dielectrophoresis approach. The simulation of floating potential distribution of the chip was performed by comsol multiphysics coupling software. Six hundred devices were assembled on the area of less than one square centimeter. The fabricated devices were characterized by atomic force microscopy and scanning electron microscopy. The experimental results showed that large-scale assembly had been realized, and the success rate of ideal assembly for SWCNT FET had been assessed.