We report a novel electric-field-enhanced chemical assembly approach for fabricating highly aligned SWNT arrays on a solid surface with remarkably improved efficiency and packing density, which is very important for the real applications of carbon nanotube arrays. With the enhancement of the electric field, the assembling kinetics of SWNTs is remarkably speeded up to effectively decrease the assembling time, and the packing density can even exceed the saturated density of conventional assembly method by four times within only half an hour. The molecular dynamics simulation results illustrated the alignment of SWNTs with their long axes along the electric flux in solution, leading to the increase of packing density and efficiency through overcoming the steric hindrance of the "giant" carbon nanotubes.